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Sample records for cubic feet jpl

  1. What will we do with 104,000,000 cubic feet of Fernald waste?

    Energy Technology Data Exchange (ETDEWEB)

    Motl, G.P.; Krieger, G.J. [Fernald Environmental Restoration Management Corp., Cincinnati, OH (United States). Fernald Environmental Management Project; Rast, D.M. [USDOE Fernald Area Office, OH (United States)

    1995-04-01

    The Fernald Site, a Department of Energy (DOE) uranium metal production facility that ceased production in 1989, is now being remediated by the DOE under terms of a Consent Agreement with the United States Environmental Protection Agency (USEPA) and a Consent Decree with the State of Ohio. It is estimated that the cleanup will generate 104,000,000 cubic feet of low-level radioactive waste including construction debris, pit sludge, radium residue and a huge volume of uranium contaminated soil. The waste handling strategy for this huge volume of waste includes minimizing remedial waste generation, recycling material when economically feasible, free-releasing clean material and volume reduction. It is anticipated that large scale radium residue vitrification and sludge drying equipment/facilities will be constructed onsite for waste treatment prior to off-site disposal. Fernald waste disposition will include both onsite disposal (if approved under CERCLA) and off-site disposal at both commercial and DOE waste disposal facilities. The waste disposition strategy selected reflects a diverse variety of technical, political, regulatory and economic factors. This presentation will describe the current views at Fernald on {open_quotes}what will we do with 104,000,000 cubic feet of Fernald waste.{close_quotes}

  2. Prosthetic Feet

    Science.gov (United States)

    ... for optional PDF format. Requires Adobe Acrobat Reader Text size Larger text Smaller text Java Required Print page Save and share Favorites ... to the hip) reduce the effort needed to control a prosthesis and keep the knee from ... need periodic repair and cost a little more than most basic feet are ...

  3. JPL Contamination Control Engineering

    Science.gov (United States)

    Blakkolb, Brian

    2013-01-01

    JPL has extensive expertise fielding contamination sensitive missions-in house and with our NASA/industry/academic partners.t Development and implementation of performance-driven cleanliness requirements for a wide range missions and payloads - UV-Vis-IR: GALEX, Dawn, Juno, WFPC-II, AIRS, TES, et al - Propulsion, thermal control, robotic sample acquisition systems. Contamination control engineering across the mission life cycle: - System and payload requirements derivation, analysis, and contamination control implementation plans - Hardware Design, Risk trades, Requirements V-V - Assembly, Integration & Test planning and implementation - Launch site operations and launch vehicle/payload integration - Flight ops center dot Personnel on staff have expertise with space materials development and flight experiments. JPL has capabilities and expertise to successfully address contamination issues presented by space and habitable environments. JPL has extensive experience fielding and managing contamination sensitive missions. Excellent working relationship with the aerospace contamination control engineering community/.

  4. JPL Innovation Foundry

    Science.gov (United States)

    Sherwood, Brent; McCleese, Daniel

    2012-01-01

    Space science missions are increasingly challenged today: in ambition, by increasingly sophisticated hypotheses tested; in development, by the increasing complexity of advanced technologies; in budgeting, by the decline of flagship-class mission opportunities; in management, by expectations for breakthrough science despite a risk-averse programmatic climate; and in planning, by increasing competition for scarce resources. How are the space-science missions of tomorrow being formulated? The paper describes the JPL Innovation Foundry, created in 2011, to respond to this evolving context. The Foundry integrates methods, tools, and experts that span the mission concept lifecycle. Grounded in JPL's heritage of missions, flight instruments, mission proposals, and concept innovation, the Foundry seeks to provide continuity of support and cost-effective, on-call access to the right domain experts at the right time, as science definition teams and Principal Investigators mature mission ideas from "cocktail napkin" to PDR. The Foundry blends JPL capabilities in proposal development and concurrent engineering, including Team X, with new approaches for open-ended concept exploration in earlier, cost-constrained phases, and with ongoing research and technology projects. It applies complexity and cost models, projectformulation lessons learned, and strategy analyses appropriate to each level of concept maturity. The Foundry is organizationally integrated with JPL formulation program offices; staffed by JPL's line organizations for engineering, science, and costing; and overseen by senior Laboratory leaders to assure experienced coordination and review. Incubation of each concept is tailored depending on its maturity and proposal history, and its highest leverage modeling and analysis needs.

  5. JPL Innovation Foundry

    Science.gov (United States)

    Sherwood, Brent; McCleese, Daniel

    2012-01-01

    Space science missions are increasingly challenged today: in ambition, by increasingly sophisticated hypotheses tested; in development, by the increasing complexity of advanced technologies; in budgeting, by the decline of flagship-class mission opportunities; in management, by expectations for breakthrough science despite a risk-averse programmatic climate; and in planning, by increasing competition for scarce resources. How are the space-science missions of tomorrow being formulated? The paper describes the JPL Innovation Foundry, created in 2011, to respond to this evolving context. The Foundry integrates methods, tools, and experts that span the mission concept lifecycle. Grounded in JPL's heritage of missions, flight instruments, mission proposals, and concept innovation, the Foundry seeks to provide continuity of support and cost-effective, on-call access to the right domain experts at the right time, as science definition teams and Principal Investigators mature mission ideas from "cocktail napkin" to PDR. The Foundry blends JPL capabilities in proposal development and concurrent engineering, including Team X, with new approaches for open-ended concept exploration in earlier, cost-constrained phases, and with ongoing research and technology projects. It applies complexity and cost models, projectformulation lessons learned, and strategy analyses appropriate to each level of concept maturity. The Foundry is organizationally integrated with JPL formulation program offices; staffed by JPL's line organizations for engineering, science, and costing; and overseen by senior Laboratory leaders to assure experienced coordination and review. Incubation of each concept is tailored depending on its maturity and proposal history, and its highest leverage modeling and analysis needs.

  6. JPL Innovation Foundry

    Science.gov (United States)

    Sherwood, Brent; McCleese, Daniel

    2013-08-01

    Space science missions are increasingly challenged today: in ambition, by increasingly sophisticated hypotheses tested; in development, by the increasing complexity of advanced technologies; in budgeting, by the decline of flagship-class mission opportunities; in management, by expectations for breakthrough science despite a risk-averse programmatic climate; and in planning, by increasing competition for scarce resources. How are the space-science missions of tomorrow being formulated? The paper describes the JPL Innovation Foundry, created in 2011, to respond to this evolving context. The Foundry integrates methods, tools, and experts that span the mission concept lifecycle. Grounded in JPL's heritage of missions, flight instruments, mission proposals, and concept innovation, the Foundry seeks to provide continuity of support and cost-effective, on-call access to the right domain experts at the right time, as science definition teams and Principal Investigators mature mission ideas from "cocktail napkin" to PDR. The Foundry blends JPL capabilities in proposal development and concurrent engineering, including Team X, with new approaches for open-ended concept exploration in earlier, cost-constrained phases, and with ongoing research and technology projects. It applies complexity and cost models, project-formulation lessons learned, and strategy analyses appropriate to each level of concept maturity. The Foundry is organizationally integrated with JPL formulation program offices; staffed by JPL's line organizations for engineering, science, and costing; and overseen by senior Laboratory leaders to assure experienced coordination and review. Incubation of each concept is tailored depending on its maturity and proposal history, and its highest-leverage modeling and analysis needs.

  7. JPL Mission Bibliometrics

    Science.gov (United States)

    Coppin, Ann

    2013-01-01

    For a number of years ongoing bibliographies of various JPL missions (AIRS, ASTER, Cassini, GRACE, Earth Science, Mars Exploration Rovers (Spirit & Opportunity)) have been compiled by the JPL Library. Mission specific bibliographies are compiled by the Library and sent to mission scientists and managers in the form of regular (usually quarterly) updates. Charts showing publications by years are periodically provided to the ASTER, Cassini, and GRACE missions for supporting Senior Review/ongoing funding requests, and upon other occasions as a measure of the impact of the missions. Basically the Web of Science, Compendex, sometimes Inspec, GeoRef and Aerospace databases are searched for the mission name in the title, abstract, and assigned keywords. All get coded for journal publications that are refereed publications.

  8. Sweaty Feet (Hyperhidrosis)

    Science.gov (United States)

    ... Feet? Excessive sweating of the feet is called hyperhidrosis. It's more common in men than in women, ... sweating of the palms. According to the International Hyperhidrosis Society, 3 percent of the population suffers from ...

  9. Why Do Feet Stink?

    Science.gov (United States)

    ... of plastic. Plastic and some human-made materials don't let your feet breathe. Go barefoot. Let your feet air out by letting them spend some time in the open air, especially at night. But don't go barefoot too much — especially in the outdoors — because ...

  10. Arthritis and the Feet

    Science.gov (United States)

    ... RSS Home » Learn About Feet » Foot Health Information Arthritis What is Arthritis? Arthritis, in general terms, is inflammation and swelling of ... an increase in the fluid in the joints. Arthritis has multiple causes; just as a sore throat ...

  11. JPL Tropical Cyclone Information System

    Data.gov (United States)

    National Aeronautics and Space Administration — The JPL Tropical Cyclone Information System (TCIS) brings together satellite and in situ data sets from various sources to help you find information for a particular...

  12. JPL Small Body Database Browser

    Data.gov (United States)

    National Aeronautics and Space Administration — The JPL Small-Body Database Browser provides data for all known asteroids and many comets. Newly discovered objects and their orbits are added on a daily basis....

  13. GPS Position Time Series @ JPL

    Science.gov (United States)

    Owen, Susan; Moore, Angelyn; Kedar, Sharon; Liu, Zhen; Webb, Frank; Heflin, Mike; Desai, Shailen

    2013-01-01

    Different flavors of GPS time series analysis at JPL - Use same GPS Precise Point Positioning Analysis raw time series - Variations in time series analysis/post-processing driven by different users. center dot JPL Global Time Series/Velocities - researchers studying reference frame, combining with VLBI/SLR/DORIS center dot JPL/SOPAC Combined Time Series/Velocities - crustal deformation for tectonic, volcanic, ground water studies center dot ARIA Time Series/Coseismic Data Products - Hazard monitoring and response focused center dot ARIA data system designed to integrate GPS and InSAR - GPS tropospheric delay used for correcting InSAR - Caltech's GIANT time series analysis uses GPS to correct orbital errors in InSAR - Zhen Liu's talking tomorrow on InSAR Time Series analysis

  14. GPS Position Time Series @ JPL

    Science.gov (United States)

    Owen, Susan; Moore, Angelyn; Kedar, Sharon; Liu, Zhen; Webb, Frank; Heflin, Mike; Desai, Shailen

    2013-01-01

    Different flavors of GPS time series analysis at JPL - Use same GPS Precise Point Positioning Analysis raw time series - Variations in time series analysis/post-processing driven by different users. center dot JPL Global Time Series/Velocities - researchers studying reference frame, combining with VLBI/SLR/DORIS center dot JPL/SOPAC Combined Time Series/Velocities - crustal deformation for tectonic, volcanic, ground water studies center dot ARIA Time Series/Coseismic Data Products - Hazard monitoring and response focused center dot ARIA data system designed to integrate GPS and InSAR - GPS tropospheric delay used for correcting InSAR - Caltech's GIANT time series analysis uses GPS to correct orbital errors in InSAR - Zhen Liu's talking tomorrow on InSAR Time Series analysis

  15. Design with the feet

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Bertelsen, Pernille; Madsen, Jacob Østergaard

    2014-01-01

    This paper presents an analysis of walking methods and their relation to participatory design (PD). The paper includes a study of walking methods found in the literature and an empirical study of transect walks in a PD project. From this analysis, we identify central attributes of, and challenges....... With this study, we take a step towards a methodological framework for "design with the feet" in PD....

  16. Why do our feet smell?

    Institute of Scientific and Technical Information of China (English)

    杨路晴

    2008-01-01

    Every night when we take off our socks and shoes,our feet smell(发出气味).The problem begjns when bacteria(细菌)are attracted(吸引)to the sweat on your feet and start eating it.The bacteria’s excretion(排泄物)has a strong smell.It causes your feet to smell badly.

  17. Space Images for NASA/JPL

    Science.gov (United States)

    Boggs, Karen; Gutheinz, Sandy C.; Watanabe, Susan M.; Oks, Boris; Arca, Jeremy M.; Stanboli, Alice; Peez, Martin; Whatmore, Rebecca; Kang, Minliang; Espinoza, Luis A.

    2010-01-01

    Space Images for NASA/JPL is an Apple iPhone application that allows the general public to access featured images from the Jet Propulsion Laboratory (JPL). A back-end infrastructure stores, tracks, and retrieves space images from the JPL Photojournal Web server, and catalogs the information into a streamlined rating infrastructure.

  18. Modernizing the JPL VLBI Correlator

    Science.gov (United States)

    Rogstad, S.; Goodhart, C. E.; Clark, J. E.; Finley, S.; Lanyi, G. E.; White, L. A.; Jacobs, Christopher S.>

    This poster will present the current capabilities of the JPL VLBI Correlator (JVC) and the general architecture of the equipment. In addition, the scientific and navigation uses of the JVC will be enumerated for background purposes. The JVC is a software correlator based on a Beowulf cluster of computers. It replaces a thirty year old correlator based on custom designed digital hardware. General comparisons between the old and new equipment will be made. The JVC makes use of a separate program, SoftC, to do the actual correlations. The JVC manages the sending of data to multiple machines in a Beowulf cluster each running SoftC in parallel on small chunks of the data. The basic architecture of SoftC will also be described.

  19. 2012 Robotics Activities at JPL

    Science.gov (United States)

    Volpe, Richard

    2012-01-01

    The Robotics Section of the Jet Propulsion Laboratory (JPL), California Institute of Technology, is engaged in a full spectrum of flight project and research activities. This paper will provide an overview of these efforts, and discuss the recent accomplishments and future directions of them. Specific activities will be high- lighted based on their level of accomplishment, impact on the community, maturity, or novelty. Robotics activities on flight projects are a significant subset of the full effort for these large missions. Complementing flight activities is a diverse set of research efforts for NASA and other U.S. Government agencies. Future directions will be motivated by NASA and other sponsor objectives, as well as success experienced in these current endeavours.

  20. Miniature JPL Universal Instrument Bus Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will transition commercial advanced- yet mature- packaging approaches, such as surface mount and system-in-package, into mainstream use at JPL. Starting...

  1. Progress in Interferometry for LISA at JPL

    CERN Document Server

    Spero, Robert; de Vine, Glenn; Dickson, Jeffrey; Klipstein, William; Ozawa, Tetsuo; McKenzie, Kirk; Shaddock, Daniel; Robison, David; Sutton, Andrew; Ware, Brent

    2011-01-01

    Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of Time Delay Interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.

  2. Progress in interferometry for LISA at JPL

    Energy Technology Data Exchange (ETDEWEB)

    Spero, Robert; Bachman, Brian; De Vine, Glenn; Dickson, Jeffrey; Klipstein, William; Ozawa, Tetsuo; McKenzie, Kirk; Shaddock, Daniel; Robison, David; Ware, Brent [Jet Propulsion Laboratory (JPL), California Institute of Technology, 4800 Oak Grove Drive Pasadena, CA 91109 (United States); Sutton, Andrew, E-mail: robert.spero@jpl.nasa.gov [Centre for Gravitational Physics, The Australian National University, ACT 0200 (Australia)

    2011-05-07

    Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of time delay interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.

  3. Cubic Subalgebras and Cubic Closed Ideals of B-algebras

    Directory of Open Access Journals (Sweden)

    Tapan Senapati

    2015-06-01

    Full Text Available In this paper, the concept of cubic set to subalgebras, ideals and closed ideals of B-algebras are introduced. Relations among cubic subalgebras with cubic ideals and cubic closed ideals of B-algebras investigated. The homomorphic image and inverse image of cubic subalgebras, ideals are studied and some related properties are investigated. Also, the product of cubic B-algebras are investigated.

  4. The JPL Neptune Radiation Model (NMOD)

    Science.gov (United States)

    Garrett, Henry; Evans, Robin

    2017-01-01

    The objective of this study is the development of a comprehensive radiation model of the Neptunian environment for JPL mission planning. The ultimate goal is to provide a description of the high-energy electron and proton environments and the magnetic field at Neptune that can be used for engineering design. The JPL Neptune Radiation Model (NMOD) models the high-energy electrons and protons between 0.025 MeV and 5 MeV based on the California Institute of Technology's Cosmic Ray Subsystem and the Applied Physics Laboratory's Low Energy Charged Particle Detector on Voyager 2. As in previous JPL radiation models, the form of the Neptunian model is based on magnetic field coordinates and requires a conversion from spacecraft coordinates to Neptunian-centered magnetic "B-L" coordinates. Two types of magnetic field models have been developed for Neptune: 1) simple "offset, tilted dipoles" (OTD), and 2) a complex, multi-pole expansion model ("O8"). A review of the existing data on Neptune and a search of the NASA Planetary Data System (PDS) were completed to obtain the most current descriptions of the Neptunian high-energy particle environment. These data were fit in terms of the O8 B-L coordinates to develop the electron and proton flux models. The flux predictions of the new model were used to estimate the total ionizing dose (TID) rate along the Neptunian equator, meridional flux contours for the electrons and protons, and for flux and dose comparisons with the other radiation belts in the Solar System.

  5. Space Images for NASA JPL Android Version

    Science.gov (United States)

    Nelson, Jon D.; Gutheinz, Sandy C.; Strom, Joshua R.; Arca, Jeremy M.; Perez, Martin; Boggs, Karen; Stanboli, Alice

    2013-01-01

    This software addresses the demand for easily accessible NASA JPL images and videos by providing a user friendly and simple graphical user interface that can be run via the Android platform from any location where Internet connection is available. This app is complementary to the iPhone version of the application. A backend infrastructure stores, tracks, and retrieves space images from the JPL Photojournal and Institutional Communications Web server, and catalogs the information into a streamlined rating infrastructure. This system consists of four distinguishing components: image repository, database, server-side logic, and Android mobile application. The image repository contains images from various JPL flight projects. The database stores the image information as well as the user rating. The server-side logic retrieves the image information from the database and categorizes each image for display. The Android mobile application is an interfacing delivery system that retrieves the image information from the server for each Android mobile device user. Also created is a reporting and tracking system for charting and monitoring usage. Unlike other Android mobile image applications, this system uses the latest emerging technologies to produce image listings based directly on user input. This allows for countless combinations of images returned. The backend infrastructure uses industry-standard coding and database methods, enabling future software improvement and technology updates. The flexibility of the system design framework permits multiple levels of display possibilities and provides integration capabilities. Unique features of the software include image/video retrieval from a selected set of categories, image Web links that can be shared among e-mail users, sharing to Facebook/Twitter, marking as user's favorites, and image metadata searchable for instant results.

  6. Einsteinian cubic gravity

    Science.gov (United States)

    Bueno, Pablo; Cano, Pablo A.

    2016-11-01

    We drastically simplify the problem of linearizing a general higher-order theory of gravity. We reduce it to the evaluation of its Lagrangian on a particular Riemann tensor depending on two parameters, and the computation of two derivatives with respect to one of those parameters. We use our method to construct a D -dimensional cubic theory of gravity which satisfies the following properties: (1) it shares the spectrum of Einstein gravity, i.e., it only propagates a transverse and massless graviton on a maximally symmetric background; (2) it is defined in the same way in general dimensions; (3) it is neither trivial nor topological in four dimensions. Up to cubic order in curvature, the only previously known theories satisfying the first two requirements are the Lovelock ones. We show that, up to cubic order, there exists only one additional theory satisfying requirements (1) and (2). Interestingly, this theory is, along with Einstein gravity, the only one which also satisfies (3).

  7. Phase mask coronagraphy at JPL and Palomar

    Directory of Open Access Journals (Sweden)

    Serabyn E.

    2011-07-01

    Full Text Available For the imaging of faint companions, phase mask coronagraphy has the dual advantages of a small inner working angle and high throughput. This paper summarizes our recent work in developing phase masks and in demonstrating their capabilities at JPL. Four-quadrant phase masks have been manufactured at JPL by means of both evaporation and etching, and we have been developing liquid crystal vortex phase masks in partnership with a commercial vendor. Both types of mask have been used with our extreme adaptive optics well-corrected subaperture at Palomar to detect known brown dwarf companions as close as ~ 2.5 λ/D to stars. Moreover, our recent vortex masks perform very well in laboratory tests, with a demonstrated infrared contrast of about 10−6 at 3 λ/D, and contrasts of a few 10−7 with an initial optical wavelength device. The demonstrated performance already meets the needs of ground-based extreme adaptive optics coronagraphy, and further planned improvements are aimed at reaching the 10−10 contrast needed for terrestrial exoplanet detection with a space-based coronagraph.

  8. JPL Space Telecommunications Radio System Operating Environment

    Science.gov (United States)

    Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.; Duncan, Courtney B.; Orozco, David S.; Stern, Ryan A.; Ahten, Earl R.; Girard, Mike

    2013-01-01

    A flight-qualified implementation of a Software Defined Radio (SDR) Operating Environment for the JPL-SDR built for the CoNNeCT Project has been developed. It is compliant with the NASA Space Telecommunications Radio System (STRS) Architecture Standard, and provides the software infrastructure for STRS compliant waveform applications. This software provides a standards-compliant abstracted view of the JPL-SDR hardware platform. It uses industry standard POSIX interfaces for most functions, as well as exposing the STRS API (Application Programming In terface) required by the standard. This software includes a standardized interface for IP components instantiated within a Xilinx FPGA (Field Programmable Gate Array). The software provides a standardized abstracted interface to platform resources such as data converters, file system, etc., which can be used by STRS standards conformant waveform applications. It provides a generic SDR operating environment with a much smaller resource footprint than similar products such as SCA (Software Communications Architecture) compliant implementations, or the DoD Joint Tactical Radio Systems (JTRS).

  9. JPL stories: story on the story (series) Careering through JPL, presented by Alice M. Fairhurst

    Science.gov (United States)

    Hendrickson, S.

    2002-01-01

    Alice Fairhurst, co-author of Effective Teaching, Effective Learning, presented an enthusiastic overview of her tenure as a JPL career development and mentoring coordinator (1991-2001). Among other things, Alice is an expert in Keirseyian Temperament and Myers-Briggs typology.

  10. Guarded Cubical Type Theory

    DEFF Research Database (Denmark)

    Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald;

    2016-01-01

    This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning with co...

  11. LDR structural technology activities at JPL

    Science.gov (United States)

    Wada, Ben

    1988-01-01

    The status of the Large Deployable Reflector (LDR) technology requirements and the availability of that technology in the next few years are summarized. The research efforts at JPL related to these technology needs are also discussed. LDR requires that a large and relatively stiff truss-type backup structure have a surface accurate to 100 microns in space (initial position with thermal distortions) and the dynamic characteristics predictable and/or measurable by on-orbit system identification for micron level motion. This motion may result from the excitation of the lower modes or from wave-type motions. It is also assumed that the LDR structure can be ground tested to validate its ability to meet mission requirements. No program manager will commit a structural design based solely on analysis, unless the analysis is backed by a validation test program.

  12. Guarded Cubical Type Theory

    DEFF Research Database (Denmark)

    Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald;

    2016-01-01

    This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning...... with coinductive types. We wish to implement GDTT with decidable type-checking, while still supporting non-trivial equality proofs that reason about the extensions of guarded recursive constructions. CTT is a variation of Martin-L\\"of type theory in which the identity type is replaced by abstract paths between...... terms. CTT provides a computational interpretation of functional extensionality, is conjectured to have decidable type checking, and has an implemented type-checker. Our new type theory, called guarded cubical type theory, provides a computational interpretation of extensionality for guarded recursive...

  13. Guarded Cubical Type Theory

    DEFF Research Database (Denmark)

    Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald;

    2016-01-01

    This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning...... with coinductive types. We wish to implement GDTT with decidable type checking, while still supporting non-trivial equality proofs that reason about the extensions of guarded recursive constructions. CTT is a variation of Martin-L\\"of type theory in which the identity type is replaced by abstract paths between...... terms. CTT provides a computational interpretation of functional extensionality, enjoys canonicity for the natural numbers type, and is conjectured to support decidable type-checking. Our new type theory, guarded cubical type theory (GCTT), provides a computational interpretation of extensionality...

  14. Diabetes - taking care of your feet

    Science.gov (United States)

    Diabetes - foot care - self-care; Diabetic foot ulcer - foot care; Diabetic neuropathy - foot care ... Diabetes can damage the nerves and blood vessels in your feet. This damage can cause numbness and ...

  15. Towards gecko-feet-inspired bandages.

    Science.gov (United States)

    Yanik, Mehmet Fatih

    2009-01-01

    A novel bandage inspired by gecko feet might one day be used during emergencies and internal surgeries. The bandage uses a combination of nanofabricated structures, biodegradable materials and adhesive surface chemistry that allows adhesion onto even wet, moving tissue.

  16. JPL Advanced Thermal Control Technology Roadmap - 2008

    Science.gov (United States)

    Birur, Gaj

    2008-01-01

    This slide presentation reviews the status of thermal control technology at JPL and NASA.It shows the active spacecraft that are in vairous positions in the solar syatem, and beyond the solar system and the future missions that are under development. It then describes the challenges that the past missions posed with the thermal control systems. The various solutions that were implemented duirng the decades prior to 1990 are outlined. A review of hte thermal challenges of the future misions is also included. The exploration plan for Mars is then reviewed. The thermal challenges of the Mars Rovers are then outlined. Also the challenges of systems that would be able to be used in to explore Venus, and Titan are described. The future space telescope missions will also need thermal control technological advances. Included is a review of the thermal requirements for manned missions to the Moon. Both Active and passive technologies that have been used and will be used are reviewed. Those that are described are Mechanically Pumped Fluid Loops (MPFL), Loop Heat Pipes, an M3 Passive Cooler, Heat Siwtch for Space and Mars surface applications, phase change material (PCM) technology, a Gas Gap Actuateor using ZrNiH(x), the Planck Sorption Cooler (PCS), vapor compression -- Hybrid two phase loops, advanced pumps for two phase cooling loops, and heat pumps that are lightweight and energy efficient.

  17. The Snow Data System at NASA JPL

    Science.gov (United States)

    Laidlaw, R.; Painter, T. H.; Mattmann, C. A.; Ramirez, P.; Brodzik, M. J.; Rittger, K.; Bormann, K. J.; Burgess, A. B.; Zimdars, P.; McGibbney, L. J.; Goodale, C. E.; Joyce, M.

    2015-12-01

    The Snow Data System at NASA JPL includes a data processing pipeline built with open source software, Apache 'Object Oriented Data Technology' (OODT). It produces a variety of data products using inputs from satellites such as MODIS, VIIRS and Landsat. Processing is carried out in parallel across a high-powered computing cluster. Algorithms such as 'Snow Covered Area and Grain-size' (SCAG) and 'Dust Radiative Forcing in Snow' (DRFS) are applied to satellite inputs to produce output images that are used by many scientists and institutions around the world. This poster will describe the Snow Data System, its outputs and their uses and applications, along with recent advancements to the system and plans for the future. Advancements for 2015 include automated daily processing of historic MODIS data for SCAG (MODSCAG) and DRFS (MODDRFS), automation of SCAG processing for VIIRS satellite inputs (VIIRSCAG) and an updated version of SCAG for Landsat Thematic Mapper inputs (TMSCAG) that takes advantage of Graphics Processing Units (GPUs) for faster processing speeds. The pipeline has been upgraded to use the latest version of OODT and its workflows have been streamlined to enable computer operators to process data on demand. Additional products have been added, such as rolling 8-day composites of MODSCAG data, a new version of the MODSCAG 'annual minimum ice and snow extent' (MODICE) product, and recoded MODSCAG data for the 'Satellite Snow Product Intercomparison and Evaluation Experiment' (SnowPEx) project.

  18. JPL Big Data Technologies for Radio Astronomy

    Science.gov (United States)

    Jones, Dayton L.; D'Addario, L. R.; De Jong, E. M.; Mattmann, C. A.; Rebbapragada, U. D.; Thompson, D. R.; Wagstaff, K.

    2014-04-01

    During the past three years the Jet Propulsion Laboratory has been working on several technologies to deal with big data challenges facing next-generation radio arrays, among other applications. This program has focused on the following four areas: 1) We are investigating high-level ASIC architectures that reduce power consumption for cross-correlation of data from large interferometer arrays by one to two orders of magnitude. The cost of operations for the Square Kilometre Array (SKA), which may be dominated by the cost of power for data processing, is a serious concern. A large improvement in correlator power efficiency could have a major positive impact. 2) Data-adaptive algorithms (machine learning) for real-time detection and classification of fast transient signals in high volume data streams are being developed and demonstrated. Studies of the dynamic universe, particularly searches for fast (system for eventual deployment on ASKAP. In addition, a real-time transient detection experiment is now running continuously and commensally on NRAO's Very Long Baseline Array. 3) Scalable frameworks for data archiving, mining, and distribution are being applied to radio astronomy. A set of powerful open-source Object Oriented Data Technology (OODT) tools is now available through Apache. OODT was developed at JPL for Earth science data archives, but it is proving to be useful for radio astronomy, planetary science, health care, Earth climate, and other large-scale archives. 4) We are creating automated, event-driven data visualization tools that can be used to extract information from a wide range of complex data sets. Visualization of complex data can be improved through algorithms that detect events or features of interest and autonomously generate images or video to display those features. This work has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  19. Anisotropic cubic curvature couplings

    CERN Document Server

    Bailey, Quentin G

    2016-01-01

    To complement recent work on tests of spacetime symmetry in gravity, cubic curvature couplings are studied using an effective field theory description of spacetime-symmetry breaking. The associated mass dimension 8 coefficients for Lorentz violation studied do not result in any linearized gravity modifications and instead are revealed in the first nonlinear terms in an expansion of spacetime around a flat background. We consider effects on gravitational radiation through the energy loss of a binary system and we study two-body orbital perturbations using the post-Newtonian metric. Some effects depend on the internal structure of the source and test bodies, thereby breaking the Weak Equivalence Principle for self-gravitating bodies. These coefficients can be measured in solar-system tests, while binary-pulsar systems and short-range gravity tests are particularly sensitive.

  20. Designing the design at JPL'S innovation foundary

    Science.gov (United States)

    Balint, Tibor S.; Freeman, Anthony

    2017-08-01

    -engineering disciplines, such as industrial and graphic design, human centered design, and even art. Communicating the information more effectively through conversations and symbolic means benefits from the skills of human centered designers and artists. In this paper we will discuss how design is being designed at JPL's Innovation Foundry, by focusing on novel languages, storytelling, conversations, boundary objects in support of improved communications both externally to stakeholders and sponsors, and internally within the design teams. We will also highlight how these new design driven approaches provide a strategic strength for the organization when competing for funding in a resource-constrained environment.

  1. Status of JPL Li-Ion Cell Development Program

    Science.gov (United States)

    Surampudi, S.; Huang, C. K.; Smart, M.; Davies, E.

    1996-01-01

    None given. This is a series of viewgraphs from a visual presentation to the workshop. From outline: JPL program overview; low temperature studies; cycle life studies; destructive physical analysis (DPA) of cycled cells; prototype cell development; summary of accomplishment.

  2. Test Waveform Applications for JPL STRS Operating Environment

    Science.gov (United States)

    Lux, James P.; Peters, Kenneth J.; Taylor, Gregory H.; Lang, Minh; Stern, Ryan A.; Duncan, Courtney B.

    2013-01-01

    This software demonstrates use of the JPL Space Telecommunications Radio System (STRS) Operating Environment (OE), tests APIs (application programming interfaces) presented by JPL STRS OE, and allows for basic testing of the underlying hardware platform. This software uses the JPL STRS Operating Environment ["JPL Space Tele com - munications Rad io System Operating Environment,"(NPO-4776) NASA Tech Briefs, commercial edition, Vol. 37, No. 1 (January 2013), p. 47] to interact with the JPL-SDR Software Defined Radio developed for the CoNNeCT (COmmunications, Navigation, and Networking rEconfigurable Testbed) Project as part of the SCaN Testbed installed on the International Space Station (ISS). These are the first applications that are compliant with the new NASA STRS Architecture Standard. Several example waveform applications are provided to demonstrate use of the JPL STRS OE for the JPL-SDR platform used for the CoNNeCT Project. The waveforms provide a simple digitizer and playback capability for the SBand RF slice, and a simple digitizer for the GPS slice [CoNNeCT Global Positioning System RF Module, (NPO-47764) NASA Tech Briefs, commercial edition, Vol. 36, No. 3 (March 2012), p. 36]. These waveforms may be used for hardware test, as well as for on-orbit or laboratory checkout. Additional example waveforms implement SpaceWire and timer modules, which can be used for time transfer and demonstration of communication between the two Xilinx FPGAs in the JPLSDR. The waveforms are also compatible with ground-based use of the JPL STRS OE on radio breadboards and Linux.

  3. Managing Friction Blisters of the Feet.

    Science.gov (United States)

    Ramsey, M L

    1992-01-01

    In brief Active people often develop friction blisters on their feet. Although such blisters rarely create significant medical problems, they can be quite painful and can hinder athletic performance. People can decrease the chance of blister formation by wearing properly fitting shoes, doubling up on socks, and applying dressings or lubricants. If lesions do develop, conservative treatment will speed healing and lessen pain and disability.

  4. Chondroblastoma of the hands and feet

    Energy Technology Data Exchange (ETDEWEB)

    Davila, Jesse A.; Amrami, Kimberly K.; Sundaram, Murali; Adkins, Mark C. [Mayo Clinic, Department of Radiology, Rochester (United States); Unni, Krishnan K. [Mayo Clinic, Department of Surgical Pathology, Rochester (United States)

    2004-10-01

    To review the imaging findings, age and gender distribution of chondroblastoma of the hands and feet. Twenty-five cases of pathologically proven chondroblastoma of the hands and feet were reviewed. Available imaging modalities included radiographs (n=24), CT (n=3), MRI (n=5), and radionuclide bone scintigraphy (n=1). The following imaging features for each case were tabulated: location, presence of sclerotic margin, calcification, expansion, presence of fluid/fluid levels on cross-sectional imaging and surrounding edema on MRI. The images were evaluated for skeletal maturity using closure of the physeal plate in the region as a standard. The average age at time of diagnosis was 23 years (range 7-57 years). Eighty-four percent (n=21) of the patients were skeletally mature. Males (20 of 25) outnumbered females by a ratio of 5:1. The bones of the foot accounted for 22 cases: calcaneus (n=8), talus (n=8), metatarsals (n=3), and the cuboid (n=3). The bones of the hand accounted for three cases: phalanx (n=1), triquetrum (n=1), and a metacarpal (n=1). Radiographically all lesions were osteolytic with identifiable calcification in 54% (13 of 24). Fluid/fluid levels were seen in four of five cases on MRI. Edema on MR images was seen in 40% (2 of 5). The size of the lesions ranged from 2 to 41 cm{sup 2}. Chondroblastomas of the hands and feet share many of the radiographic characteristics seen in the long bones, but manifest in skeletally mature patients with a higher male to female ratio than in long bone chondroblastoma. Talar and calcaneal lesions were encountered only in males. Chondroblastoma of the wrist and hand appears to be exceptionally rare. (orig.)

  5. A Cubic Tree Taper Model

    National Research Council Canada - National Science Library

    Goodwin, Adrian N

    2009-01-01

    A flexible tree taper model based on a cubic polynomial is described. It is algebraically invertible and integrable, and can be constrained by one or two diameters, neither of which need be diameter at breast height (DBH...

  6. Software risk estimation and management techniques at JPL

    Science.gov (United States)

    Hihn, J.; Lum, K.

    2002-01-01

    In this talk we will discuss how uncertainty has been incorporated into the JPL software model, probabilistic-based estimates, and how risk is addressed, how cost risk is currently being explored via a variety of approaches, from traditional risk lists, to detailed WBS-based risk estimates to the Defect Detection and Prevention (DDP) tool.

  7. The JPL Cost Risk Analysis Approach that Incorporates Engineering Realism

    Science.gov (United States)

    Harmon, Corey C.; Warfield, Keith R.; Rosenberg, Leigh S.

    2006-01-01

    This paper discusses the JPL Cost Engineering Group (CEG) cost risk analysis approach that accounts for all three types of cost risk. It will also describe the evaluation of historical cost data upon which this method is based. This investigation is essential in developing a method that is rooted in engineering realism and produces credible, dependable results to aid decision makers.

  8. The JPL Cost Risk Analysis Approach that Incorporates Engineering Realism

    Science.gov (United States)

    Harmon, Corey C.; Warfield, Keith R.; Rosenberg, Leigh S.

    2006-01-01

    This paper discusses the JPL Cost Engineering Group (CEG) cost risk analysis approach that accounts for all three types of cost risk. It will also describe the evaluation of historical cost data upon which this method is based. This investigation is essential in developing a method that is rooted in engineering realism and produces credible, dependable results to aid decision makers.

  9. Universal Reconfiguration of (Hyper-)cubic Robots

    OpenAIRE

    Abel, Zachary; Kominers, Scott D.

    2008-01-01

    We study a simple reconfigurable robot model which has not been previously examined: cubic robots comprised of three-dimensional cubic modules which can slide across each other and rotate about each others' edges. We demonstrate that the cubic robot model is universal, i.e., that an n-module cubic robot can reconfigure itself into any specified n-module configuration. Additionally, we provide an algorithm that efficiently plans and executes cubic robot motion. Our results directly extend to a...

  10. Cubication of Conservative Nonlinear Oscillators

    Science.gov (United States)

    Belendez, Augusto; Alvarez, Mariela L.; Fernandez, Elena; Pascual, Immaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear…

  11. Cryptographic Analysis in Cubic Time

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Seidl, H.

    2004-01-01

    The spi-calculus is a variant of the polyadic pi-calculus that admits symmetric cryptography and that admits expressing communication protocols in a precise though still abstract way. This paper shows that context-independent control flow analysis can be calculated in cubic time despite the fact ...

  12. The diagonalization of cubic matrices

    Science.gov (United States)

    Cocolicchio, D.; Viggiano, M.

    2000-08-01

    This paper is devoted to analysing the problem of the diagonalization of cubic matrices. We extend the familiar algebraic approach which is based on the Cardano formulae. We rewrite the complex roots of the associated resolvent secular equation in terms of transcendental functions and we derive the diagonalizing matrix.

  13. Protection of feet in cold exposure.

    Science.gov (United States)

    Kuklane, Kalev

    2009-07-01

    The paper summarizes the research on cold protection of feet. There exist several conflicting requirements for the choice of the best suited footwear for cold exposure. These conflicts are related to various environmental factors, protection needs and user comfort issues. In order to reduce such conflicts and simplify the choice of proper footwear the paper suggests dividing the cold into specific ranges that are related to properties and state of water and its possibility to penetrate into, evaporate from or condensate in footwear. The thermo-physiological background and reactions in foot are briefly explained, and main problems and risks related to cold injuries, mechanical injuries and slipping discussed. Footwear thermal insulation is the most important factor for protection against cold. The issues related to measuring the insulation and the practical use of measured values are described, but also the effect of socks, and footwear size. Other means for reducing heat losses, such as PCM and electrical heating are touched. The most important variable that affects footwear thermal insulation and foot comfort is moisture in footwear. In combination with motion they may reduce insulation and thus protection against cold by 45%. The paper includes recommendations for better foot comfort in cold.

  14. Mobile Timekeeping Application Built on Reverse-Engineered JPL Infrastructure

    Science.gov (United States)

    Witoff, Robert J.

    2013-01-01

    Every year, non-exempt employees cumulatively waste over one man-year tracking their time and using the timekeeping Web page to save those times. This app eliminates this waste. The innovation is a native iPhone app. Libraries were built around a reverse- engineered JPL API. It represents a punch-in/punch-out paradigm for timekeeping. It is accessible natively via iPhones, and features ease of access. Any non-exempt employee can natively punch in and out, as well as save and view their JPL timecard. This app is built on custom libraries created by reverse-engineering the standard timekeeping application. Communication is through custom libraries that re-route traffic through BrowserRAS (remote access service). This has value at any center where employees track their time.

  15. Galileo Press Conference from JPL. Parts 1 and 2

    Science.gov (United States)

    1992-01-01

    This two-tape Jet Propulsion Laboratory (JPL) video production presents a Dec. 8, 1992 press conference held at JPL to discuss the final Galileo spacecraft encounter with Earth before beginning its journey to Jupiter. The main theme of the conference was centered on the significance of the 2nd and final Earth/Moon flyby as being the spacecraft's last planetary encounter in the solar system before reaching Jupiter, as well as final flight preparations prior to its final journey. Each person of the five member panel was introduced by Robert MacMillan (JPL Public Information Mgr.) before giving brief presentations including slides and viewgraphs covering their area of expertise regarding Galileo's current status and future plans. After the presentations, the media was given an opportunity to ask questions of the panel regarding the mission. Mr. Wesley Huntress (Dir. of Solar System Exploration (NASA)), William J. ONeill (Galileo Project Manager), Neal E. Ausman, Jr. (Galileo Mission Director), Dr. Torrence V. Johnson (Galileo Project Scientist) and Dr. Ronald Greeley (Member, Imaging Team, Colorado St. Univ.) made up the panel and discussed topics including: Galileo's interplanetary trajectory; project status and performance review; instrument calibration activities; mission timelines; lunar observation and imaging; and general lunar science. Also included in the last three minutes of the video are simulations and images of the 2nd Galileo/Moon encounter.

  16. (abstract) JPL Cryocooler Development and Test Program Overview

    Science.gov (United States)

    Ross, R. G.

    1994-01-01

    Many near-term and future space-instrument programs within NASA and the Ballistic Missile Defense Organization (BMDO) depend on the successful development of long-life, low-vibration space cryocoolers. The most demanding near-term programs include a number of science instruments selected for NASA's Earth Observing System (Eos) program, and a number of space reconnaissance instruments associated with the BMDO's Brilliant Eyes program; both of these programs require delivery of similar types of flight coolers in the next few years. To help ensure the success of these cooler commitments, JPL has implemented an extensive cryocooler program in support of the NASA/JPL AIRS project, the Air Force Phillips Laboratory (AFPL), and the Air Force Space and Missiles Systems Division (SMC). This program is directed at assisting industry in developing advanced cryocoolers that successfully address the broad array of complex performance requirements needed for NASA and BMDO long-life space instruments. The JPL cryocooler program includes extensive characterization and life testing of industry-developed cryocoolers, development and flight testing of advanced sorption cooler systems for detector cooling to 10 K , development of mechanical cryocooler enhancement technologies, and flight tests of advanced low-vibration Stirling-cooler systems.

  17. Data Management System Reuse for Visualization of JPL's SMAP Project

    Science.gov (United States)

    Alarcon, C.; Huang, T.; Roberts, J. T.; Rodriguez, J. D.; Quach, N. T.; De Cesare, C.; Hall, J. R.

    2015-12-01

    The Imagery Exchange (TIE) is a scalable and efficient imagery data management system that powers the WMS web server OnEarth. Designed and developed at the Jet Propulsion Laboratory (JPL), TIE's primary purpose was to power the NASA's Global Imagery Browse Services (GIBS), a system that provides full resolution imagery from a broad set of Earth science disciplines to the public. The SMAP project at JPL had just about all of its requirements met with GIBS but required very project-specific behavior and automation for the Cal-Val phase of the project. Thanks to the extendable design of TIE (already an extension of JPL's Horizon framework) and Amazon's GovCloud services, we were able to meet the needs of the project without any rewrite of the system while significantly expanding the capabilities of an already robust system through well modularized feature additions. In this presentation, we will talk about the efforts made to re-use the already developed data system TIE for SMAP with minimal turn around. Leveraging cloud resources and standard interfaces, we were able to satisfy new project requirements in a very short amount of time.

  18. From the Field: Carbofuran detected on weathered raptor carcass feet

    Science.gov (United States)

    Vyas, N.B.; Spann, J.W.; Hulse, C.S.; Bauer, W.; Olson, S.

    2005-01-01

    The cause of death for raptors poisoned at illegal carbofuran-Iaced predator baits is often not confirmed because the carcass matrices that are conventionally analyzed are not available due to decomposition and scavenging. However, many such carcasses retain intact feet that may have come into contact with carbofuran. Eastern screech owls (Otus asio) were exposed to carbofuran via simulated predator baits. Detection of carbofuran from owl feet weathered for 28 days demonstrated the temporal reliability of using feet during a forensic investigation. Raptor carcasses previously not submitted for residue analysis because of a lack of the conventional matrices may now be salvaged for their feet.

  19. Cubication of conservative nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Belendez, Augusto; Alvarez, Mariela L [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain); Fernandez, Elena; Pascual, Inmaculada [Departamento de Optica, FarmacologIa y Anatomia, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)], E-mail: a.belendez@ua.es

    2009-09-15

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear and cubic terms depend on the initial amplitude, A, while in a Taylor expansion of the restoring force these coefficients are independent of A. The replacement of the original nonlinear equation by an approximate Duffing equation allows us to obtain an approximate frequency-amplitude relation as a function of the complete elliptic integral of the first kind. Some conservative nonlinear oscillators are analysed to illustrate the usefulness and effectiveness of this scheme.

  20. Cubic Matrix, Nambu Mechanics and Beyond

    OpenAIRE

    Kawamura, Y

    2002-01-01

    We propose a generalization of cubic matrix mechanics by introducing a canonical triplet and study its relation to Nambu mechanics. The generalized cubic matrix mechanics we consider can be interpreted as a “quantum” generalization of Nambu mechanics.

  1. Cubical sets and the topological topos

    DEFF Research Database (Denmark)

    Spitters, Bas

    2016-01-01

    Coquand's cubical set model for homotopy type theory provides the basis for a computational interpretation of the univalence axiom and some higher inductive types, as implemented in the cubical proof assistant. This paper contributes to the understanding of this model. We make three contributions...... show that it can also be a target for cubical realization by showing that Coquand's cubical sets classify the geometric theory of flat distributive lattices. As a side result, we obtain a simplicial realization of a cubical set. 2. Using the internal `interval' in the topos of cubical sets, we...... construct a Moore path model of identity types. 3. We construct a premodel structure internally in the cubical type theory and hence on the fibrant objects in cubical sets....

  2. Numbers for reducible cubic scrolls

    Directory of Open Access Journals (Sweden)

    Israel Vainsencher

    2004-12-01

    Full Text Available We show how to compute the number of reducible cubic scrolls of codimension 2 in (math blackboard symbol Pn incident to the appropriate number of linear spaces.Mostramos como calcular o número de rolos cúbicos redutíveis de codimensão 2 em (math blackboard symbol Pn incidentes a espaços lineares apropriados.

  3. Career in Feet-on Seismology

    Science.gov (United States)

    Van der Lee, S.

    2011-12-01

    My career award was for imaging the upper mantle beneath North America. The research proposed was timely because of Earthscope and novel because of the proposed simultaneous inversion of different types of seismic data as well as the inclusion of mineral physics data on the effects of volatiles on seismic properties of the mantle. This research has been challenging and fun and is still on-going. The educational component of my career award consists of feet-on and eyes-open learning of seismology through an educational kiosk and field trips to actual seismic stations. The kiosk and field station have both been growing over the years, as has the audience. I started with the field station in-doors, so it doubled as the kiosk along with a palmtop terminal. Groups of minority elementary school children would look at the mysterious hardware of the "field" station and then jump up and down so they could awe at the peaks in the graph on the palmtop screen that they created. This has evolved into a three-screen kiosk, of which one screen is a touch screen along with a demonstration seismometer. The field station is now in a goat shed near the epicenter of an actual 2010 earthquake inIllinois, which is soon to be replaced by a TA station of Earthscope. The audience has grown to entire grades of middle-school children and activities have evolved from jumping to team-experimentation and the derivation of amplitude-distance relationships following a collaborative curriculum. Addressing the questions in the session description: 1) Education is more fun and effective when one can work in a team with an enthusiastic educator. 2) My education activities are strongly related to my field of expertise but very loosely related to the research carried out with the career award. It appears that not the research outcomes are of interest to students, but instead the simplification and accessibility of the process of research that is of interest. 3) The education component of the career

  4. Cubic colloids : Synthesis, functionalization and applications

    NARCIS (Netherlands)

    Castillo, S.I.R.

    2015-01-01

    This thesis is a study on cubic colloids: micron-sized cubic particles with rounded corners (cubic superballs). Owing to their shape, particle packing for cubes is more efficient than for spheres and results in fascinating phase and packing behavior. For our cubes, the particle volume fraction when

  5. Cubic colloids : Synthesis, functionalization and applications

    NARCIS (Netherlands)

    Castillo, S.I.R.

    2015-01-01

    This thesis is a study on cubic colloids: micron-sized cubic particles with rounded corners (cubic superballs). Owing to their shape, particle packing for cubes is more efficient than for spheres and results in fascinating phase and packing behavior. For our cubes, the particle volume fraction when

  6. Solving Cubic Equations by Polynomial Decomposition

    Science.gov (United States)

    Kulkarni, Raghavendra G.

    2011-01-01

    Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…

  7. Cubic Icosahedra? A Problem in Assigning Symmetry

    Science.gov (United States)

    Lloyd, D. R.

    2010-01-01

    There is a standard convention that the icosahedral groups are classified separately from the cubic groups, but these two symmetry types have been conflated as "cubic" in some chemistry textbooks. In this note, the connection between cubic and icosahedral symmetries is examined, using a simple pictorial model. It is shown that octahedral and…

  8. Scatterometry Products Distributed by JPL PO.DAAC

    Science.gov (United States)

    Chen, R. L.; Lungu, T.; Benada, J. R.

    2001-12-01

    The Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the Jet Propulsion Laboratory (JPL) archives and distributes physical oceanography data, including data from spacebased scatterometers. PO.DAAC's current archive contains more than six terabytes of scatterometry data, and PO.DAAC has distributed over 40 terabytes of that data to users worldwide. Those numbers increase steadily with the continuation of the QuikSCAT satellite, and that increase should effectively double with the pending launch of SeaWinds on ADEOS-II. The SeaWinds on QuikSCAT instrument provides the largest component of PO.DAAC's scatterometry data. Every day, the instrument makes 400,000 measurements and covers 90% of the ice-free oceans for wind data, with additional useful information over land and ice. PO.DAAC publicly distributes two QuikSCAT products: - Level 3 Daily, Gridded Ocean Wind Vectors (JPL SeaWinds Project) - Level 2B Ocean Wind Vectors in 25 Km Swath Grid (JPL SeaWinds Project) Scheduled to launch in February 2002, the SeaWinds on ADEOS-II instrument will provide a similar amount of data as QuikSCAT. PO.DAAC will again publicly distribute the level 2B and the level 3 products. Other scatterometry data currently available from PO.DAAC include: - BYU Daily Browse Images of QuikSCAT Sigma-0 Measurements (D. Long) - NSCAT Scatterometer ocean wind products - NSCAT Scatterometer Science Product, Levels 1.7, 2, 3 - NSCAT scatterometer global 25km sigma-0 and ocean winds (Dunbar) Samples of some of these datasets are presented.

  9. An evaluation of the 1997 JPL Summer Teacher Enhancement Program

    Energy Technology Data Exchange (ETDEWEB)

    Slovacek, Simeon P.; Doyle-Nichols, Adelaide R.

    1997-10-20

    There were two major components in the Jet Propulsion Laboratory (JPL) Summer Teacher Enhancement Project (STEP). First, the Summer Institute was structured as a four-week, 4-credit-unit University course for middle school science teachers, and consisted of workshops, lectures, labs, and tours as activities. The second component consists of follow-up activities related to the summer institute's contents, and again is structured as a University credit-bearing course for participants to reinforce their summer training. Considerable information from the comments and course ratings as given by the participants is included.

  10. A brief review of JPL's electric propulsion technology activities

    Science.gov (United States)

    Barnett, John W.; Chopra, Ann; Deininger, William D.; Garner, Charles E.; Pivirotto, Thomas J.; Sercel, Joel C.

    1989-01-01

    Near-term objectives and recent technological progress of JPL's electric propulsion program are discussed. Particular attention is given to accomplishments for ion, magnetoplasmadynamic (MPD), electron-cyclotron resonance (ECR), and arcjet thrusters. Xenon ion thruster erosion tests indicate a 15-fold reduction in tantalum baffle erosion when nitrogen is added to the xenon propellant and steady-state cylindrical MPD thruster tests at powers up to 72 kW show distinct self-constricted and diffuse discharge modes. An ECR thruster was operated at up to 7 kW with plasma acceleration at energies up to 7 kW; there was plasma acceleration at energies approaching 100 electron volts.

  11. JPL multipolarization workstation - Hardware, software and examples of data analysis

    Science.gov (United States)

    Burnette, Fred; Norikane, Lynne

    1987-01-01

    A low-cost stand-alone interactive image processing workstation has been developed for operations on multipolarization JPL aircraft SAR data, as well as data from future spaceborne imaging radars. A recently developed data compression technique is used to reduce the data volume to 10 Mbytes, for a typical data set, so that interactive analysis may be accomplished in a timely and efficient manner on a supermicrocomputer. In addition to presenting a hardware description of the work station, attention is given to the software that has been developed. Three illustrative examples of data analysis are presented.

  12. Cubic metaplectic forms and theta functions

    CERN Document Server

    Proskurin, Nikolai

    1998-01-01

    The book is an introduction to the theory of cubic metaplectic forms on the 3-dimensional hyperbolic space and the author's research on cubic metaplectic forms on special linear and symplectic groups of rank 2. The topics include: Kubota and Bass-Milnor-Serre homomorphisms, cubic metaplectic Eisenstein series, cubic theta functions, Whittaker functions. A special method is developed and applied to find Fourier coefficients of the Eisenstein series and cubic theta functions. The book is intended for readers, with beginning graduate-level background, interested in further research in the theory of metaplectic forms and in possible applications.

  13. Weighted cubic and biharmonic splines

    Science.gov (United States)

    Kvasov, Boris; Kim, Tae-Wan

    2017-01-01

    In this paper we discuss the design of algorithms for interpolating discrete data by using weighted cubic and biharmonic splines in such a way that the monotonicity and convexity of the data are preserved. We formulate the problem as a differential multipoint boundary value problem and consider its finite-difference approximation. Two algorithms for automatic selection of shape control parameters (weights) are presented. For weighted biharmonic splines the resulting system of linear equations can be efficiently solved by combining Gaussian elimination with successive over-relaxation method or finite-difference schemes in fractional steps. We consider basic computational aspects and illustrate main features of this original approach.

  14. Improved Infrastucture for Cdms and JPL Molecular Spectroscopy Catalogues

    Science.gov (United States)

    Endres, Christian; Schlemmer, Stephan; Drouin, Brian; Pearson, John; Müller, Holger S. P.; Schilke, P.; Stutzki, Jürgen

    2014-06-01

    Over the past years a new infrastructure for atomic and molecular databases has been developed within the framework of the Virtual Atomic and Molecular Data Centre (VAMDC). Standards for the representation of atomic and molecular data as well as a set of protocols have been established which allow now to retrieve data from various databases through one portal and to combine the data easily. Apart from spectroscopic databases such as the Cologne Database for Molecular Spectroscopy (CDMS), the Jet Propulsion Laboratory microwave, millimeter and submillimeter spectral line catalogue (JPL) and the HITRAN database, various databases on molecular collisions (BASECOL, KIDA) and reactions (UMIST) are connected. Together with other groups within the VAMDC consortium we are working on common user tools to simplify the access for new customers and to tailor data requests for users with specified needs. This comprises in particular tools to support the analysis of complex observational data obtained with the ALMA telescope. In this presentation requests to CDMS and JPL will be used to explain the basic concepts and the tools which are provided by VAMDC. In addition a new portal to CDMS will be presented which has a number of new features, in particular meaningful quantum numbers, references linked to data points, access to state energies and improved documentation. Fit files are accessible for download and queries to other databases are possible.

  15. Transparent polycrystalline cubic silicon nitride

    Science.gov (United States)

    Nishiyama, Norimasa; Ishikawa, Ryo; Ohfuji, Hiroaki; Marquardt, Hauke; Kurnosov, Alexander; Taniguchi, Takashi; Kim, Byung-Nam; Yoshida, Hidehiro; Masuno, Atsunobu; Bednarcik, Jozef; Kulik, Eleonora; Ikuhara, Yuichi; Wakai, Fumihiro; Irifune, Tetsuo

    2017-01-01

    Glasses and single crystals have traditionally been used as optical windows. Recently, there has been a high demand for harder and tougher optical windows that are able to endure severe conditions. Transparent polycrystalline ceramics can fulfill this demand because of their superior mechanical properties. It is known that polycrystalline ceramics with a spinel structure in compositions of MgAl2O4 and aluminum oxynitride (γ-AlON) show high optical transparency. Here we report the synthesis of the hardest transparent spinel ceramic, i.e. polycrystalline cubic silicon nitride (c-Si3N4). This material shows an intrinsic optical transparency over a wide range of wavelengths below its band-gap energy (258 nm) and is categorized as one of the third hardest materials next to diamond and cubic boron nitride (cBN). Since the high temperature metastability of c-Si3N4 in air is superior to those of diamond and cBN, the transparent c-Si3N4 ceramic can potentially be used as a window under extremely severe conditions. PMID:28303948

  16. Microbiological evaluation of chicken feet intended for human consumption

    Directory of Open Access Journals (Sweden)

    Ana Paula Dutra Resem Brizio

    2013-12-01

    Full Text Available Chicken feet are products with great commercial importance for the eastern markets. Although Brazil is a large exporter of these products to those markets, little information is available on the sanitary quality of these products. The objective of this study was to evaluate the microbiological quality of frozen chicken feet for human consumption. This study was developed in a slaughterhouse under Federal Inspection, located in the state of Rio Grande do Sul. A total of 98 samples of frozen chicken feet were analyzed, between January and December 2011, for the detection of Salmonella spp., total count of mesophilic bacteria, total coliforms, fecal coliforms, Escherichia coli, Staphylococcus coagulase positive and Clostridium perfringens. About 99% of the results were within the microbiological standards established by the Chinese (world´s largest importer and Brazilian legislation for raw chicken meat. Thus, we conclude that the samples of frozen chicken feet showed satisfactory microbiological quality and no risk to consumer health.

  17. POSTURAL DISTURBANCES AND FEET DEFORMITIES IN CHILDREN WITH CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    V. M. Kenis

    2011-01-01

    Full Text Available The purpose of study was to estimate common postural disturbances in children with cerebral palsy in relation to feet deformities. 100 children were investigated. Age-related changes in postural patterns are described. Five stereotypical postural patterns are most common in children with cerebral palsy. Proper management of feet deformities is necessary for correction of postural disturbance. Inadequate surgical treatment, as a contrast, may be harmfull and dangerous.

  18. POSTURAL DISTURBANCES AND FEET DEFORMITIES IN CHILDREN WITH CEREBRAL PALSY

    OpenAIRE

    V. M. Kenis; Ivanov, S V; Yu. A. Stepanova

    2011-01-01

    The purpose of study was to estimate common postural disturbances in children with cerebral palsy in relation to feet deformities. 100 children were investigated. Age-related changes in postural patterns are described. Five stereotypical postural patterns are most common in children with cerebral palsy. Proper management of feet deformities is necessary for correction of postural disturbance. Inadequate surgical treatment, as a contrast, may be harmfull and dangerous.

  19. Tame Kernels of Pure Cubic Fields

    Institute of Scientific and Technical Information of China (English)

    Xiao Yun CHENG

    2012-01-01

    In this paper,we study the p-rank of the tame kernels of pure cubic fields.In particular,we prove that for a fixed positive integer m,there exist infinitely many pure cubic fields whose 3-rank of the tame kernel equal to m.As an application,we determine the 3-rank of their tame kernels for some special pure cubic fields.

  20. Two-dimensional cubic convolution.

    Science.gov (United States)

    Reichenbach, Stephen E; Geng, Frank

    2003-01-01

    The paper develops two-dimensional (2D), nonseparable, piecewise cubic convolution (PCC) for image interpolation. Traditionally, PCC has been implemented based on a one-dimensional (1D) derivation with a separable generalization to two dimensions. However, typical scenes and imaging systems are not separable, so the traditional approach is suboptimal. We develop a closed-form derivation for a two-parameter, 2D PCC kernel with support [-2,2] x [-2,2] that is constrained for continuity, smoothness, symmetry, and flat-field response. Our analyses, using several image models, including Markov random fields, demonstrate that the 2D PCC yields small improvements in interpolation fidelity over the traditional, separable approach. The constraints on the derivation can be relaxed to provide greater flexibility and performance.

  1. JPL Project Information Management: A Continuum Back to the Future

    Science.gov (United States)

    Reiz, Julie M.

    2009-01-01

    This slide presentation reviews the practices and architecture that support information management at JPL. This practice has allowed concurrent use and reuse of information by primary and secondary users. The use of this practice is illustrated in the evolution of the Mars Rovers from the Mars Pathfinder to the development of the Mars Science Laboratory. The recognition of the importance of information management during all phases of a project life cycle has resulted in the design of an information system that includes metadata, has reduced the risk of information loss through the use of an in-process appraisal, shaping of project's appreciation for capturing and managing the information on one project for re-use by future projects as a natural outgrowth of the process. This process has also assisted in connection of geographically disbursed partners into a team through sharing information, common tools and collaboration.

  2. JPL Project Information Management: A Continuum Back to the Future

    Science.gov (United States)

    Reiz, Julie M.

    2009-01-01

    This slide presentation reviews the practices and architecture that support information management at JPL. This practice has allowed concurrent use and reuse of information by primary and secondary users. The use of this practice is illustrated in the evolution of the Mars Rovers from the Mars Pathfinder to the development of the Mars Science Laboratory. The recognition of the importance of information management during all phases of a project life cycle has resulted in the design of an information system that includes metadata, has reduced the risk of information loss through the use of an in-process appraisal, shaping of project's appreciation for capturing and managing the information on one project for re-use by future projects as a natural outgrowth of the process. This process has also assisted in connection of geographically disbursed partners into a team through sharing information, common tools and collaboration.

  3. Cubical local partial orders on cubically subdivided spaces - Existence and construction

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth

    2006-01-01

    The geometric models of higher dimensional automata (HDA) and Dijkstra's PV-model are cubically subdivided topological spaces with a local partial order. If a cubicalization of a topological space is free of immersed cubic Möbius bands, then there are consistent choices of direction in all cubes...

  4. Cubical local partial orders on cubically subdivided spaces - existence and construction

    DEFF Research Database (Denmark)

    Fajstrup, Lisbeth

    The geometric models of Higher Dimensional Automata and Dijkstra's PV-model are cubically subdivided topological spaces with a local partial order. If a cubicalization of a topological space is free of immersed cubic Möbius bands, then there are consistent choices of direction in all cubes...

  5. CLASSIFICATION OF CUBIC PARAMETERIZED HOMOGENEOUS VECTOR FIELDS

    Institute of Scientific and Technical Information of China (English)

    Karnal H.Yasir; TANG Yun

    2002-01-01

    In this paper the cubic homogeneous parameterized vector fields are studied.The classification of the phase portrait near the critical point is presented. This classification is an extension of the result given by Takens to the cubic homogeneous parameterized vector fields with six parameters.

  6. CLASSIFICATION OF CUBIC PARAMETERIZED HOMOGENEOUS VECTOR FIELDS

    Institute of Scientific and Technical Information of China (English)

    KamalH.Yasir; TNAGYun

    2002-01-01

    In this paper the cubic homogeneous parameterized vector fields are studied.The classification of the phase portrait near the critical point is presented.This classification is an extension of the result given by takens to the cubic homogeneous parameterized vector fields with six parameters.

  7. Project Bibliographies: Tracking the Expansion of Knowledge Using JPL Project Publications

    Science.gov (United States)

    Coppin, Ann

    2016-01-01

    The Jet Propulsion Laboratory (JPL) Library defines a project bibliography as a bibliography of publicly available publications relating to a specific JPL instrument or mission. These bibliographies may be used to share information between distant project team members, as part of the required Education and Public Outreach effort, or as part of…

  8. Fibromatosis over the dorsa of both feet: An unusual presentation

    Science.gov (United States)

    Kishan Kumar, Y. Hari; Sujatha, C.; Jayaprasad, Sushmitha

    2015-01-01

    Fibromatosis is benign fibrous tissue condition intermediate between benign fibroma and metastasizing fibrosarcoma. The lesion tends to infiltrate and recur when removed, but do not metastasize. The lesion may be single or multiple, and the likelihood of recurrence after surgical removal varies with location of the lesion and age. A 40-year-old female presented with multiple raised lesions over both feet since 4 years, they were multiple well-defined firm nodules coalescing to form lobulated plaques distributed in a symmetrical pattern over the dorsum of both feet. Histopathology of skin showed epidermis with hyperkeratosis, acanthosis, mild parakeratosis, and prominent granular layer. Superficial dermis was unremarkable and deep dermis showed thick bundles of irregular collagen and fibroblastic proliferation, suggestive of fibromatosis. This case is being reported for its unusual presentation of fibromatosis over the dorsum of both feet. PMID:25821730

  9. The JPL Millimeter and Submillimeter Spectral Line Catalog

    Science.gov (United States)

    Drouin, Brian J.; Yu, Shanshan; Pearson, John C.

    2010-06-01

    A makeover of the JPL Millimeter and Submillimeter Spectral Line Catalog has begun. This process is intended to provide ` single-line-access' to users and virtual astronomy facilities through a server/query interface. In order to provide these users with the maximum amount of reliability and trace-ability, the database format (traditionally ascii-text files on an http/ftp server) has been expanded to include data and data-sources in a format where the measurement data is listed independently of the model predicted line information. This information, although still accessible through the source text-files, is also compiled into a MySQL database. This methodology allows merging of measurement and prediction to be done at the meta-data level and gives the user quick access to the literature source. The creation of virtual observatories will give the astronomer a new interface tool, that, without this improved access, would otherwise be blind to much of the source information that has traditionally been kept in documentary files intended for human processing. As the users develop their model(s) to understand real astrophysical data, the virtual observatory, with open online database access, will fill the role of analysis tool, or perhaps provide input to it, and these format changes will allow the astrometric tools to track the catalog's sources/updates.

  10. Ultrahard nanotwinned cubic boron nitride.

    Science.gov (United States)

    Tian, Yongjun; Xu, Bo; Yu, Dongli; Ma, Yanming; Wang, Yanbin; Jiang, Yingbing; Hu, Wentao; Tang, Chengchun; Gao, Yufei; Luo, Kun; Zhao, Zhisheng; Wang, Li-Min; Wen, Bin; He, Julong; Liu, Zhongyuan

    2013-01-17

    Cubic boron nitride (cBN) is a well known superhard material that has a wide range of industrial applications. Nanostructuring of cBN is an effective way to improve its hardness by virtue of the Hall-Petch effect--the tendency for hardness to increase with decreasing grain size. Polycrystalline cBN materials are often synthesized by using the martensitic transformation of a graphite-like BN precursor, in which high pressures and temperatures lead to puckering of the BN layers. Such approaches have led to synthetic polycrystalline cBN having grain sizes as small as ∼14 nm (refs 1, 2, 4, 5). Here we report the formation of cBN with a nanostructure dominated by fine twin domains of average thickness ∼3.8 nm. This nanotwinned cBN was synthesized from specially prepared BN precursor nanoparticles possessing onion-like nested structures with intrinsically puckered BN layers and numerous stacking faults. The resulting nanotwinned cBN bulk samples are optically transparent with a striking combination of physical properties: an extremely high Vickers hardness (exceeding 100 GPa, the optimal hardness of synthetic diamond), a high oxidization temperature (∼1,294 °C) and a large fracture toughness (>12 MPa m(1/2), well beyond the toughness of commercial cemented tungsten carbide, ∼10 MPa m(1/2)). We show that hardening of cBN is continuous with decreasing twin thickness down to the smallest sizes investigated, contrasting with the expected reverse Hall-Petch effect below a critical grain size or the twin thickness of ∼10-15 nm found in metals and alloys.

  11. Cubic III-nitrides: potential photonic materials

    Science.gov (United States)

    Onabe, K.; Sanorpim, S.; Kato, H.; Kakuda, M.; Nakamura, T.; Nakamura, K.; Kuboya, S.; Katayama, R.

    2011-01-01

    The growth and characterization of some cubic III-nitride films on suitable cubic substrates have been done, namely, c- GaN on GaAs by MOVPE, c-GaN and c-AlGaN on MgO by RF-MBE, and c-InN and c-InGaN (In-rich) on YSZ by RFMBE. This series of study has been much focused on the cubic-phase purity as dependent on the respective growth conditions and resulting electrical and optical properties. For c-GaN and c-InN films, a cubic-phase purity higher than 95% is attained in spite of the metastable nature of the cubic III-nitrides. However, for c-AlGaN and c-InGaN films, the cubic-phase purity is rapidly degraded with significant incorporation of the hexagonal phase through stacking faults on cubic {111} faces which may be exposed on the roughened growing or substrate surface. It has been shown that the electron mobilities in c-GaN and c-AlGaN films are much related to phase purity.

  12. Cubic Curves, Finite Geometry and Cryptography

    CERN Document Server

    Bruen, A A; Wehlau, D L

    2011-01-01

    Some geometry on non-singular cubic curves, mainly over finite fields, is surveyed. Such a curve has 9,3,1 or 0 points of inflexion, and cubic curves are classified accordingly. The group structure and the possible numbers of rational points are also surveyed. A possible strengthening of the security of elliptic curve cryptography is proposed using a `shared secret' related to the group law. Cubic curves are also used in a new way to construct sets of points having various combinatorial and geometric properties that are of particular interest in finite Desarguesian planes.

  13. Generalized Vaidya spacetime for cubic gravity

    CERN Document Server

    Ruan, Shan-Ming

    2015-01-01

    We present a kind of generalized Vaidya solutions of a new cubic gravity in five dimensions whose field equations in spherically spacetime are always second order like the Lovelock gravity. We also study the thermodynamics of its apparent horizon and get its entropy expression and generalized Misner-Sharp energy. Finally we present the first law and second law hold in this gravity. Although all the results are analogue to those in Lovelock gravity, we in fact introduce the contribution of new cubic term in five dimensions where cubic Lovelock term is just zero.

  14. Cubical sets as a classifying topos

    DEFF Research Database (Denmark)

    Spitters, Bas

    Coquand’s cubical set model for homotopy type theory provides the basis for a computational interpretation of the univalence axiom and some higher inductive types, as implemented in the cubical proof assistant. We show that the underlying cube category is the opposite of the Lawvere theory of De...... Morgan algebras. The topos of cubical sets itself classifies the theory of ‘free De Morgan algebras’. This provides us with a topos with an internal ‘interval’. Using this interval we construct a model of type theory following van den Berg and Garner. We are currently investigating the precise relation...

  15. Patch testing in contact dermatitis of hands and feet

    Directory of Open Access Journals (Sweden)

    Huda M

    1996-01-01

    Full Text Available Eighty clinically diagnosed cases of allergic contact dermatitis of hands and feet when subjected to patch testing, Seventy four (92.5% cases showed positive patch test reactions to different suspected antigens. Maximum number of cases belonged to housewives and tea garden workers which showed positive patch test reaction to vegetables and soaps and detergents and pesticides, respectively.

  16. Comparative roll-over analysis of prosthetic feet

    NARCIS (Netherlands)

    Curtze, Carolin; Hof, At L.; van Keeken, Helco G.; Halbertsma, Jan P. K.; Postema, Klaas; Otten, Bert

    2009-01-01

    A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a pe

  17. Advances in Propulsive Bionic Feet and Their Actuation Principles

    Directory of Open Access Journals (Sweden)

    Pierre Cherelle

    2014-07-01

    Full Text Available In the past decades, researchers have deeply studied pathological and nonpathological gait to understand the human ankle function during walking. These efforts resulted in the development of new lower limb prosthetic devices aiming at raising the 3C-level (control, comfort, and cosmetics of amputees. Thanks to the technological advances in engineering and mechatronics, challenges in the field of prosthetics have become an important source of interest for roboticists. Currently, most of the bionic feet are still on a research level but show promising results and a preview of tomorrow's commercial prosthetic devices. In this paper, the authors present the current state-of-the-art and the latest advances in propulsive bionic feet with its actuation principles. The context of this review study is outlined followed by a brief description of the basics in human biomechanics and criteria for new prosthetic designs. A new categorization based on the actuation principle of propulsive ankle-foot prostheses is proposed. Based on simulations, the general principles and benefits of each actuation method are explained. The corresponding latest advances in propulsive bionic feet are presented together with their main characteristics and scientific outcomes. The authors also propose to the reader a comparison analysis of the presented devices with a discussion of the general tendencies in new prosthetic feet.

  18. Burning feet syndrome: An old tropical syndrome revisited

    Directory of Open Access Journals (Sweden)

    Ellen Welch

    2013-01-01

    Full Text Available Background: Burning feet syndrome (BFS has been described anecdotally in the literature for over 200 years. Described subjectively by patients as burning, prickling and unremitting with nocturnal exacerbations, the condition draws parallels with the burning dysaesthesia found in diabetic peripheral neuropathy, and appears to display a similar chronicity. Despite being a common symptom, especially among the elderly, its etiology in non-specific and often marked by a lack of objective clinical signs. Historically, burning feet syndrome has been recorded in situations of poor nutrition, including malnourished African populations in the early 20th century, South American plantation workers in the 1920s and during food shortages in the Spanish Civil War. Perhaps the best described and largest outbreak of burning feet occurred amongst prisoners of war (POWs of the Japanese during the 2nd World War in South East Asia and the Far East. In this review we summarise reports of the condition, in particular amongst Far East POWs (FEPOWs, using both the available literature as well as a unique and previously unknown contemporary study carried out in a POW camp. Materials and Methods: During his stay in the Tandjung Priok POW camp, Nowell Peach recorded 54 cases of burning feet seen over a 4 month period during captivity. This data was concealed from his captors and survived to return home with him. Results: 54 prisoners presented over a 4 month period with a mean age of 28 years and mean duration of symptoms of 12 weeks. Neurological signs were meticulously documented. All were on an inadequate diet, 20 (38% were on less than a full ration. Accompanying tropical infections were common including malaria (73%, dengue (45% and dysentery (41%. Discussions: The Peach survey confirmed the frequency of burning feet amongst FEPOWs and was unusual in that the neurological examination and conditions endured were documented in captivity. A paucity of physical signs was

  19. Flexible flat feet in children: a real problem?

    Science.gov (United States)

    García-Rodríguez, A; Martín-Jiménez, F; Carnero-Varo, M; Gómez-Gracia, E; Gómez-Aracena, J; Fernández-Crehuet, J

    1999-06-01

    To estimate the prevalence of flexible flat feet in the provincial population of 4- to 13-year-old schoolchildren and the incidence of treatments considered unnecessary. Province of Málaga, Spain. We examined and graded by severity a sample of 1181 pupils taken from a total population of 198 858 primary schoolchildren (CI: 95%; margin of error: 5%). The sample group was separated into three 2-year age groups: 4 and 5 years, 8 and 9 years, and 12 and 13 years. The plantar footprint was classified according to Denis1 into three grades of flat feet: grade 1 in which support of the lateral edge of the foot is half that of the metatarsal support; grade 2 in which the support of the central zone and forefoot are equal; and grade 3 in which the support in the central zone of the foot is greater than the width of the metatarsal support. The statistical analysis for the evaluation of the differences between the groups was performed with Student's t and chi2 tests as appropriate. The prevalence of flat feet was 2.7%. Of the 1181 children sampled, 168 children (14.2%) were receiving orthopedic treatment, but only 2.7% had diagnostic criteria of flat feet. When we inspected the sample, we found that a number of children were being treated for flat feet with boots and arch supports. Most of them did not have a flat plantar footprint according to the criteria that we used for this work. Furthermore, in the group of children that we diagnosed as having flat feet, only 28.1% were being treated. We found no significant differences between the number of children receiving orthopedic treatments and the presence or absence of a flat plantar footprint. Children who were overweight in the 4- and 5-year-old group showed an increased prevalence for flat feet as diagnosed by us. The data suggest that an excessive number of orthopedic treatments had been prescribed in the province. When extrapolated to the 1997 population of schoolchildren within the age groups studied the figures

  20. MOVING SCREW DISLOCATION IN CUBIC QUASICRYSTAL

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wang-min; SONG Yu-hai

    2005-01-01

    The elasticity theory of the dislocation of cubic quasicrystals is developed.The governing equations of anti-plane elasticity dynamics problem of the quasicrystals were reduced to a solution of wave equations by introducing displacement functions,and the analytical expressions of displacements, stresses and energies induced by a moving screw dislocation in the cubic quasicrystalline and the velocity limit of the dislocation were obtained. These provide important information for studying the plastic deformation of the new solid material.

  1. 2-rational Cubic Spline Involving Tension Parameters

    Indian Academy of Sciences (India)

    M Shrivastava; J Joseph

    2000-08-01

    In the present paper, 1-piecewise rational cubic spline function involving tension parameters is considered which produces a monotonic interpolant to a given monotonic data set. It is observed that under certain conditions the interpolant preserves the convexity property of the data set. The existence and uniqueness of a 2-rational cubic spline interpolant are established. The error analysis of the spline interpolant is also given.

  2. Semisymmetric Cubic Graphs of Order 162

    Indian Academy of Sciences (India)

    Mehdi Alaeiyan; Hamid A Tavallaee; B N Onagh

    2010-02-01

    An undirected graph without isolated vertices is said to be semisymmetric if its full automorphism group acts transitively on its edge set but not on its vertex set. In this paper, we inquire the existence of connected semisymmetric cubic graphs of order 162. It is shown that for every odd prime , there exists a semisymmetric cubic graph of order 162 and its structure is explicitly specified by giving the corresponding voltage rules generating the covering projections.

  3. Cubical version of combinatorial differential forms

    DEFF Research Database (Denmark)

    Kock, Anders

    2010-01-01

    The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry.......The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry....

  4. Planning the future of JPL's management and administrative support systems around an integrated database

    Science.gov (United States)

    Ebersole, M. M.

    1983-01-01

    JPL's management and administrative support systems have been developed piece meal and without consistency in design approach over the past twenty years. These systems are now proving to be inadequate to support effective management of tasks and administration of the Laboratory. New approaches are needed. Modern database management technology has the potential for providing the foundation for more effective administrative tools for JPL managers and administrators. Plans for upgrading JPL's management and administrative systems over a six year period evolving around the development of an integrated management and administrative data base are discussed.

  5. A cognitive operating system (COGNOSYS) for JPL's robot, phase 1 report

    Science.gov (United States)

    Mathur, F. P.

    1972-01-01

    The most important software requirement for any robot development is the COGNitive Operating SYStem (COGNOSYS). This report describes the Stanford University Artificial Intelligence Laboratory's hand eye software system from the point of view of developing a cognitive operating system for JPL's robot. In this, the Phase 1 of the JPL robot COGNOSYS task the installation of a SAIL compiler and a FAIL assembler on Caltech's PDP-10 have been accomplished and guidelines have been prepared for the implementation of a Stanford University type hand eye software system on JPL-Caltech's computing facility. The alternatives offered by using RAND-USC's PDP-10 Tenex operating sytem are also considered.

  6. Planning the future of JPL's management and administrative support systems around an integrated database

    Science.gov (United States)

    Ebersole, M. M.

    1983-01-01

    JPL's management and administrative support systems have been developed piece meal and without consistency in design approach over the past twenty years. These systems are now proving to be inadequate to support effective management of tasks and administration of the Laboratory. New approaches are needed. Modern database management technology has the potential for providing the foundation for more effective administrative tools for JPL managers and administrators. Plans for upgrading JPL's management and administrative systems over a six year period evolving around the development of an integrated management and administrative data base are discussed.

  7. Comparing Arc-shaped Feet and Rigid Ankles with Flat Feet and Compliant Ankles for a Dynamic Walker

    DEFF Research Database (Denmark)

    Kuhlemann, Ilyas; Matthias Braun, Jan; Wörgötter, Florentin

    2014-01-01

    walking robot RunBot, controlled by an reflexive neural network, uses only few sensors for generating its stable gait. The results show that at feet and compliant ankles extend RunBot's parameter range especially to more leaning back postures. They also allow the robot to stably walk over obstacles...

  8. JPL Genesis and Rapid Intensification Processes (GRIP) Portal

    Science.gov (United States)

    Knosp, Brian W.; Li, P. Peggy; Vu, Quoc A.; Turk, Francis J.; Shen, Tsae-Pyng J.; Hristova-Veleva, Svetla M.; Licata, Stephen J.; Poulsen, William L.

    2012-01-01

    Satellite observations can play a very important role in airborne field campaigns, since they provide a comprehensive description of the environment that is essential for the experiment design, flight planning, and post-experiment scientific data analysis. In the past, it has been difficult to fully utilize data from multiple NASA satellites due to the large data volume, the complexity of accessing NASA s data in near-real-time (NRT), as well as the lack of software tools to interact with multi-sensor information. The JPL GRIP Portal is a Web portal that serves a comprehensive set of NRT observation data sets from NASA and NOAA satellites describing the atmospheric and oceanic environments related to the genesis and intensification of the tropical storms in the North Atlantic Ocean. Together with the model forecast data from four major global atmospheric models, this portal provides a useful tool for the scientists and forecasters in planning and monitoring the NASA GRIP field campaign during the 2010 Atlantic Ocean hurricane season. This portal uses the Google Earth plug-in to visualize various types of data sets, such as 2D maps, wind vectors, streamlines, 3D data sets presented at series of vertical cross-sections or pointwise vertical profiles, and hurricane best tracks and forecast tracks. Additionally, it allows users to overlap multiple data sets, change the opacity of each image layer, generate animations on the fly with selected data sets, and compare the observation data with the model forecast using two independent calendars. The portal also provides the capability to identify the geographic location of any point of interest. In addition to supporting the airborne mission planning, the NRT data and portal will serve as a very rich source of information during the post-field campaign analysis stage of the airborne experiment. By including a diverse set of satellite observations and model forecasts, it provides a good spatial and temporal context for the

  9. Increase in efficiency of game by feet in modern rugby

    Directory of Open Access Journals (Sweden)

    Volodymyr Mucha

    2017-02-01

    Full Text Available Purpose: to define the importance of successful carrying out kicks of realization in rugby for the end result of the match. Material & Methods: the analysis of scientifically-methodical literature and the analysis of the developed results of matches in the rugby World Cups. Results: the reasons of the developed structure of effectiveness in rugby are described; the developed analysis of results of the final part of the World Cups in rugby of 2011 and 2015 is submitted. Conclusions: the significant place is taken not only by the brought attempts, and both their successful realization and other game elements by feet because of the high density of the final results and high level of preparedness of teams. The detailed analysis of results of the research demonstrates what not only realization is of great importance in points taking for the final result, but also all kicks by feet what their big percent at points taking testifies to.

  10. Cows-feet soup: a rare cause of recurrent trichobezoar.

    Science.gov (United States)

    Kiernan, Miles Finbar; Kamat, Sachin; Olagbaiye, Femi

    2012-01-01

    A 45-year-old Afro-Caribbean woman attended the emergency department with worsening dysphagia, abdominal distension, abdominal pain, shortness of breath and generalised weakness. She enjoyed preparing and eating cows-feet stew and preferred to cook the meat with the hair and skin intact. On admission she had a severe microcytic anaemia and was malnourished. Abdominal x-ray and CT revealed a large gastric bezoar. At gastrotomy a foul-smelling 2.42 kg mass of hair, leathery skin and altered food were evacuated from the lesser curvature of the stomach. She had undergone the same procedure 8 years earlier to remove a similar trichobezoar. Following psychiatric review it was deemed that the patient had no underlying psychiatric condition and had full insight into why her trichobezoar had re-occurred. She made a good postoperative recovery and stopped eating cows-feet stew.

  11. Incidence and management of ulcers in diabetic Charcot feet.

    Science.gov (United States)

    Larsen, K; Fabrin, J; Holstein, P E

    2001-09-01

    This study followed 115 patients with diabetes--who between them had 140 feet with Charcot's arthropathy--over six to 114 months (median: 48). A total of 43 patients (37%) developed ulcers in 53 feet. Their treatment was multifactorial. An offloading regimen was adopted, with the use of crutches and therapeutic sandals with soft, individually moulded insoles, followed by adjusted or bespoke shoes. Recalcitrant ulcers were treated with surgery in 16 patients (37%). Antibiotics were needed by 21 patients (49%). The incidence of ulceration was 17% per year. The median time interval between the acute component of Charcot's arthropathy and ulcer development was 36 months (range: 0-120 months). In seven patients, the ulcer developed during the acute phase. In 12 patients the ulcers were localised to the rockerbottom deformity in the mid-foot region, but in 31 patients other regions were affected. Dynamic footprint analysis was used to help adjust the offloading shoe/insole on the rockerbottom deformity. Such ulcers took twice as long to heal as other ulcers. Surgical treatment comprised: major amputation (two patients), arthrodesis for unstable ankle (three patients), toe amputations (seven patients), resection of the rockerbottom deformity (one patient) and other revisions (three patients). One patient died with an unhealed ulcer. There is a four-fold risk of ulcers in diabetic Charcot deformity compared with the overall risk of foot ulcers in diabetic feet. Healing was achieved in 40 patients (93%). The surgical intervention rate of 37% in ulcer cases in Charcot feet was low compared with the literature.

  12. Interpolation by two-dimensional cubic convolution

    Science.gov (United States)

    Shi, Jiazheng; Reichenbach, Stephen E.

    2003-08-01

    This paper presents results of image interpolation with an improved method for two-dimensional cubic convolution. Convolution with a piecewise cubic is one of the most popular methods for image reconstruction, but the traditional approach uses a separable two-dimensional convolution kernel that is based on a one-dimensional derivation. The traditional, separable method is sub-optimal for the usual case of non-separable images. The improved method in this paper implements the most general non-separable, two-dimensional, piecewise-cubic interpolator with constraints for symmetry, continuity, and smoothness. The improved method of two-dimensional cubic convolution has three parameters that can be tuned to yield maximal fidelity for specific scene ensembles characterized by autocorrelation or power-spectrum. This paper illustrates examples for several scene models (a circular disk of parametric size, a square pulse with parametric rotation, and a Markov random field with parametric spatial detail) and actual images -- presenting the optimal parameters and the resulting fidelity for each model. In these examples, improved two-dimensional cubic convolution is superior to several other popular small-kernel interpolation methods.

  13. Superhard BC(3) in cubic diamond structure.

    Science.gov (United States)

    Zhang, Miao; Liu, Hanyu; Li, Quan; Gao, Bo; Wang, Yanchao; Li, Hongdong; Chen, Changfeng; Ma, Yanming

    2015-01-01

    We solve the crystal structure of recently synthesized cubic BC(3) using an unbiased swarm structure search, which identifies a highly symmetric BC(3) phase in the cubic diamond structure (d-BC(3)) that contains a distinct B-B bonding network along the body diagonals of a large 64-atom unit cell. Simulated x-ray diffraction and Raman peaks of d-BC(3) are in excellent agreement with experimental data. Calculated stress-strain relations of d-BC(3) demonstrate its intrinsic superhard nature and reveal intriguing sequential bond-breaking modes that produce superior ductility and extended elasticity, which are unique among superhard solids. The present results establish the first boron carbide in the cubic diamond structure with remarkable properties, and these new findings also provide insights for exploring other covalent solids with complex bonding configurations.

  14. Cubical Cohomology Ring of 3D Photographs

    CERN Document Server

    Gonzalez-Diaz, Rocio; Medrano, Belen; 10.1002/ima.20271

    2011-01-01

    Cohomology and cohomology ring of three-dimensional (3D) objects are topological invariants that characterize holes and their relations. Cohomology ring has been traditionally computed on simplicial complexes. Nevertheless, cubical complexes deal directly with the voxels in 3D images, no additional triangulation is necessary, facilitating efficient algorithms for the computation of topological invariants in the image context. In this paper, we present formulas to directly compute the cohomology ring of 3D cubical complexes without making use of any additional triangulation. Starting from a cubical complex $Q$ that represents a 3D binary-valued digital picture whose foreground has one connected component, we compute first the cohomological information on the boundary of the object, $\\partial Q$ by an incremental technique; then, using a face reduction algorithm, we compute it on the whole object; finally, applying the mentioned formulas, the cohomology ring is computed from such information.

  15. Purely cubic action for string field theory

    Science.gov (United States)

    Horowitz, G. T.; Lykken, J.; Rohm, R.; Strominger, A.

    1986-01-01

    It is shown that Witten's (1986) open-bosonic-string field-theory action and a closed-string analog can be written as a purely cubic interaction term. The conventional form of the action arises by expansion around particular solutions of the classical equations of motion. The explicit background dependence of the conventional action via the Becchi-Rouet-Stora-Tyutin operator is eliminated in the cubic formulation. A closed-form expression is found for the full nonlinear gauge-transformation law.

  16. Purely cubic action for string field theory

    Science.gov (United States)

    Horowitz, G. T.; Lykken, J.; Rohm, R.; Strominger, A.

    1986-01-01

    It is shown that Witten's (1986) open-bosonic-string field-theory action and a closed-string analog can be written as a purely cubic interaction term. The conventional form of the action arises by expansion around particular solutions of the classical equations of motion. The explicit background dependence of the conventional action via the Becchi-Rouet-Stora-Tyutin operator is eliminated in the cubic formulation. A closed-form expression is found for the full nonlinear gauge-transformation law.

  17. Design with the feet: walking methods and participatory design

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Bertelsen, Pernille; Madsen, Jacob Østergaard

    2014-01-01

    This paper presents an analysis of walking methods and their relation to participatory design (PD). The paper includes a study of walking methods found in the literature and an empirical study of transect walks in a PD project. From this analysis, we identify central attributes of, and challenges...... to, PD walks. Walking with people in the context of design is a natural activity for the participatory designer, who acknowledges the importance of immersion and relationships in design. However, the various intentions of walking approaches indicate an underacknowledged awareness of walking methods....... With this study, we take a step towards a methodological framework for "design with the feet" in PD....

  18. Feet swelling in a multistage ultraendurance triathlete: a case study

    Directory of Open Access Journals (Sweden)

    Knechtle B

    2015-10-01

    Full Text Available Beat Knechtle,1 Matthias Alexander Zingg,2 Patrizia Knechtle,1 Thomas Rosemann,2 Christoph Alexander Rüst2 1Gesundheitszentrum St Gallen, St Gallen, 2Institute of Primary Care, University of Zurich, Zurich, Switzerland Abstract: Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass, foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na+] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was

  19. Fabrication of duck's feet collagen-silk hybrid biomaterial for tissue engineering.

    Science.gov (United States)

    Kim, Soo Hyeon; Park, Hae Sang; Lee, Ok Joo; Chao, Janet Ren; Park, Hyun Jung; Lee, Jung Min; Ju, Hyung Woo; Moon, Bo Mi; Park, Ye Ri; Song, Jeong Eun; Khang, Gilson; Park, Chan Hum

    2016-04-01

    Collagen constituting the extracellular matrix has been widely used as biocompatible material for human use. In this study, we have selected duck's feet for extracting collagen. A simple method not utilizing harsh chemical had been employed to extract collagen from duck's feet. We fabricated duck's feet collagen/silk hybrid scaffold for the purpose of modifying the degradation rate of duck's feet collagen. This study suggests that extracted collagen from duck's feet is biocompatible and resembles collagen extracted from porcine which is commercially used. Duck's feet collagen is also economically feasible and it could therefore be a good candidate as a tissue engineering material. Further, addition of silk to fabricate a duck's feet collagen/silk hybrid scaffold could enhance the biostability of duck's feet collagen scaffold. Duck's feet collagen/silk scaffold increased the cell viability compared to silk alone. Animal studies also showed that duck's feet collagen/silk scaffold was more biocompatible than silk alone and more biostable than duck's feet or porcine collagen alone. Additionally, the results revealed that duck's feet collagen/silk hybrid scaffold had high porosity, cell infiltration and proliferation. We suggest that duck's feet collagen/silk hybrid scaffold could be used as a dermal substitution for full thickness skin defects.

  20. DEFICIENT CUBIC SPLINES WITH AVERAGE SLOPE MATCHING

    Institute of Scientific and Technical Information of China (English)

    V. B. Das; A. Kumar

    2005-01-01

    We obtain a deficient cubic spline function which matches the functions with certain area matching over a greater mesh intervals, and also provides a greater flexibility in replacing area matching as interpolation. We also study their convergence properties to the interpolating functions.

  1. Counting rational points on cubic curves

    Institute of Scientific and Technical Information of China (English)

    HEATH-BROWN; Roger; TESTA; Damiano

    2010-01-01

    We prove upper bounds for the number of rational points on non-singular cubic curves defined over the rationals.The bounds are uniform in the curve and involve the rank of the corresponding Jacobian.The method used in the proof is a combination of the "determinant method" with an m-descent on the curve.

  2. CONSTRAINED RATIONAL CUBIC SPLINE AND ITS APPLICATION

    Institute of Scientific and Technical Information of China (English)

    Qi Duan; Huan-ling Zhang; Xiang Lai; Nan Xie; Fu-hua (Frank) Cheng

    2001-01-01

    In this paper, a kind of rational cubic interpolation functionwith linear denominator is constructed. The constrained interpolation with constraint on shape of the interpolating curves and on the second-order derivative of the interpolating function is studied by using this interpolation, and as the consequent result, the convex interpolation conditions have been derived.

  3. Anisotropy of a cubic ferromagnet at criticality

    Science.gov (United States)

    Kudlis, A.; Sokolov, A. I.

    2016-10-01

    Critical fluctuations change the effective anisotropy of cubic ferromagnet near the Curie point. If the crystal undergoes phase transition into orthorhombic phase and the initial anisotropy is not too strong, reduced anisotropy of nonlinear susceptibility acquires at Tc the universal value δ4*=2/v* 3 (u*+v*) where u* and v* are coordinates of the cubic fixed point on the flow diagram of renormalization group equations. In the paper, the critical value of the reduced anisotropy is estimated within the pseudo-ɛ expansion approach. The six-loop pseudo-ɛ expansions for u*, v*, and δ4* are derived for the arbitrary spin dimensionality n . For cubic crystals (n =3 ) higher-order coefficients of the pseudo-ɛ expansions obtained turn out to be so small that use of simple Padé approximants yields reliable numerical results. Padé resummation of the pseudo-ɛ series for u*, v*, and δ4* leads to the estimate δ4*=0.079 ±0.006 , indicating that detection of the anisotropic critical behavior of cubic ferromagnets in physical and computer experiments is certainly possible.

  4. Binomial Squares in Pure Cubic Number Fields

    CERN Document Server

    Lemmermeyer, Franz

    2011-01-01

    Let K = Q(\\omega) with \\omega^3 = m be a pure cubic number field. We show that the elements\\alpha \\in K^\\times whose squares have the form a - \\omega form a group isomorphic to the group of rational points on the elliptic curve E_m: y^2= x^3 - m.

  5. The cactus rank of cubic forms

    CERN Document Server

    Bernardi, Alessandra

    2011-01-01

    We prove that the smallest degree of an apolar 0-dimensional scheme to a general cubic form in $n+1$ variables is at most $2n+2$, when $n\\geq 8$, and therefore smaller than the rank of the form. When n=8 we show that the bound is sharp, i.e. the smallest degree of an apolar subscheme is 18.

  6. Friction force reduction triggers feet grooming behaviour in beetles.

    Science.gov (United States)

    Hosoda, Naoe; Gorb, Stanislav N

    2011-06-01

    In insects, cleaning (grooming) of tarsal attachment devices is essential for maintaining their adhesive ability, necessary for walking on a complex terrain of plant surfaces. How insects obtain information on the degree of contamination of their feet has remained, until recently, unclear. We carried out friction force measurements on walking beetles Gastrophysa viridula (Coleoptera, Chrysomelidae) and counted grooming occurrence on stiff polymer substrata with different degrees of nanoroughness (root mean square: 28-288 nm). Since nanoscopically, rough surfaces strongly reduced friction and adhesion without contaminating feet, we were able to demonstrate, for the first time to our knowledge, that friction force between tarsal attachment pads and the substrate provides an insect with information on the degree of contamination of its attachment structures. We have shown that foot grooming occurrence correlates not only with the degree of contamination but also with the decrease of friction force. This result indicates that insects obtain information about the degree of contamination, not statically but rather dynamically and, presumably, use mechanoreceptors monitoring either tensile/compressive forces in the cuticle or tensile forces between leg segments.

  7. Ytterbium: Transition at High Pressure from Face-Centered Cubic to Body-Centered Cubic Structure.

    Science.gov (United States)

    Hall, H T; Barnett, J D; Merrill, L

    1963-01-11

    Pressure of 40,000 atmospheres at 25 degrees C induces a phase transformation in ytterbium metal; the face-centered cubic structure changes to body-centered cubic. The radius of the atom changes from 1.82 to 1.75 A. At the same time the atom's volume decreases by 11 percent and the volume, observed macroscopically, decreases 3.2 percent.

  8. Multimission Telemetry Visualization (MTV) system: A mission applications project from JPL's Multimedia Communications Laboratory

    Science.gov (United States)

    Koeberlein, Ernest, III; Pender, Shaw Exum

    1994-01-01

    This paper describes the Multimission Telemetry Visualization (MTV) data acquisition/distribution system. MTV was developed by JPL's Multimedia Communications Laboratory (MCL) and designed to process and display digital, real-time, science and engineering data from JPL's Mission Control Center. The MTV system can be accessed using UNIX workstations and PC's over common datacom and telecom networks from worldwide locations. It is designed to lower data distribution costs while increasing data analysis functionality by integrating low-cost, off-the-shelf desktop hardware and software. MTV is expected to significantly lower the cost of real-time data display, processing, distribution, and allow for greater spacecraft safety and mission data access.

  9. NASA-JPL overview, space technology and relevance to medicine (Conference Presentation)

    Science.gov (United States)

    van Zyl, Jakob

    2017-05-01

    There is special synergy between NASA space instruments and medical devices, especially those that may be implanted in the human body. For example, in both cases instruments have to be small, typically have to consume little power and often have to operate in harsh environments. JPL has a long history in using this synergy to leverage from the technology developed for space missions for application in medical fields. In this talk, we discuss the general overlap of technological requirements in the medical field and space science. We will highlight some examples where JPL instrumentation and engineering has been transferred successfully.

  10. Electric vehicle chassis dynamometer test methods at JPL and their correlation to track tests

    Science.gov (United States)

    Marte, J.; Bryant, J.

    1983-01-01

    Early in its electric vehicle (EV) test program, JPL recognized that EV test procedures were too vague and too loosely defined to permit much meaningful data to be obtained from the testing. Therefore, JPL adopted more stringent test procedures and chose the chassis dynamometer rather than the track as its principal test technique. Through the years, test procedures continued to evolve towards a methodology based on chassis dynamometers which would exhibit good correlation with track testing. Based on comparative dynamometer and track test results on the ETV-1 vehicle, the test methods discussed in this report demonstrate a means by which excellent track-to-dynamometer correlation can be obtained.

  11. Stationary Apparatus Would Apply Forces of Walking to Feet

    Science.gov (United States)

    Hauss, Jessica; Wood, John; Budinoff, Jason; Correia, Michael; Albrecht, Rudolf

    2006-01-01

    A proposed apparatus would apply controlled cyclic forces to both feet for the purpose of preventing the loss of bone density in a human subject whose bones are not subjected daily to the mechanical loads of normal activity in normal Earth gravitation. The apparatus was conceived for use by astronauts on long missions in outer space; it could also be used by bedridden patients on Earth, including patients too weak to generate the necessary forces by their own efforts. The apparatus (see figure) would be a modified version of a bicycle-like exercise machine, called the cycle ergometer with vibration isolation system (CEVIS), now aboard the International Space Station. Attached to each CEVIS pedal would be a computer-controlled stress/ vibration exciter connected to the heel portion of a special-purpose pedal. The user would wear custom shoes that would amount to standard bicycle shoes equipped with cleats for secure attachment of the balls of the feet to the special- purpose pedals. If possible, prior to use of the apparatus, the human subject would wear a portable network of recording accelerometers, while walking, jogging, and running. The information thus gathered would be fed to the computer, wherein it would be used to make the exciters apply forces and vibrations closely approximating the forces and vibrations experienced by that individual during normal exercise. It is anticipated that like the forces applied to bones during natural exercise, these artificial forces would stimulate the production of osteoblasts (bone-forming cells), as needed to prevent or retard loss of bone mass. In addition to helping to prevent deterioration of bones, the apparatus could be used in treating a person already suffering from osteoporosis. For this purpose, the magnitude of the applied forces could be reduced, if necessary, to a level at which weak hip and leg bones would still be stimulated to produce osteoblasts without exposing them to the full stresses of walking and

  12. Face-Centered-Cubic Nanostructured Polymer Foams

    Science.gov (United States)

    Cui, C.; Baughman, R. H.; Liu, L. M.; Zakhidov, A. A.; Khayrullin, I. I.

    1998-03-01

    Beautifully iridescent polymer foams having Fm-3m cubic symmetry and periodicities on the scale of the wavelength of light have been synthesized by the templating of porous synthetic opals. These fabrication processes involve the filling of porous SiO2 opals (with typical cubic lattice parameters of 250 nm) with either polymers or polymer precursors, polymerization of the precursors if necessary, and removal of the fcc array of SiO2 balls to provide an all-polymer structure. The structures of these foams are similar to periodic minimal surfaces, although the Gaussian curvature can have both positive and negative values. Depending upon whether the internal surfaces of the opal are polymer filled or polymer coated, the polymer replica has either one or two sets of independent channels. We fill these channels with semiconductors, metals, or superconductors to provide electronic and optical materials with novel properties dependent on the nanoscale periodicity.

  13. Cubic Polynomials with Rational Roots and Critical Points

    Science.gov (United States)

    Gupta, Shiv K.; Szymanski, Waclaw

    2010-01-01

    If you want your students to graph a cubic polynomial, it is best to give them one with rational roots and critical points. In this paper, we describe completely all such cubics and explain how to generate them.

  14. Use of Pom Pons to Illustrate Cubic Crystal Structures.

    Science.gov (United States)

    Cady, Susan G.

    1997-01-01

    Describes a method that uses olefin pom pons to illustrate cubic crystal structure. Facilitates hands-on examination of different packing arrangements such as hexagonal close-packed and cubic close-packed structures. (JRH)

  15. Shape preserving rational bi-cubic function

    Directory of Open Access Journals (Sweden)

    Malik Zawwar Hussain

    2012-11-01

    Full Text Available The study is dedicated to the development of shape preserving interpolation scheme for monotone and convex data. A rational bi-cubic function with parameters is used for interpolation. To preserve the shape of monotone and convex data, the simple data dependent constraints are developed on these parameters in each rectangular patch. The developed scheme of this paper is confined, cheap to run and produce smooth surfaces.

  16. Cubic Lienard Equations with Quadratic Damping (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Yu-quan Wang; Zhu-jun Jing

    2002-01-01

    Applying Hopf bifurcation theory and qualitative theory, we show that the general cubic Lienard equations with quadratic damping have at most three limit cycles. This implies that the guess in which the system has at most two limit cycles is false. We give the sufficient conditions for the system has at most three limit cycles or two limit cycles. We present two examples with three limit cycles or two limit cycles by using numerical simulation.

  17. Energy storage and release of prosthetic feet. Part 2: subjective ratings of 2 energy storing and 2 conventional feet, user choice of foot and deciding factor

    NARCIS (Netherlands)

    Postema, K.; Hermens, Hermanus J.; de Vries, J.; de Vries, J.; Koopman, Hubertus F.J.M.; Eisma, W.H.

    1997-01-01

    This paper is the second part of a study on biomechanical and functional properties of prosthetic feet. The first part dealt with a biomechanical analysis related to user benefits. This part deals with subjective ratings and deciding factors for trans-tibial amputees using 2 energy storing feet (ESF

  18. Energy storage and release of prosthetic feet Part 2: Subjective ratings of 2 energy storing and 2 conventional feet, user choice of foot and deciding factor

    NARCIS (Netherlands)

    Postema, K.; Hermens, H.J.; Vries, de J.; Koopman, H.F.J.M.; Eisma, W.H.

    1997-01-01

    This paper is the second part of a study on biomechanical and functional properties of prosthetic feet. The first part dealt with a biomechanical analysis related to user benefits. This part deals with subjective ratings and deciding factors for trans-tibial amputees using 2 energy storing feet (ESF

  19. Local atomic structure in cubic stabilized zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Villella, P.; Conradson, S. D.; Espinosa-Faller, F. J.; Foltyn, S. R.; Sickafus, K. E.; Valdez, J. A.; Degueldre, C. A.

    2001-09-01

    X-ray-absorption fine structure measurements have been used to elucidate the local atomic structure of quaternary Zr, Y, Er, Ce/U cubic stabilized zirconia. These compounds display more complicated local environments than those reported for simpler binary systems. While the shortest cation-O distances are similar to those found in the binary cubic stabilized compounds, responding to the different sizes of the cations, we have identified large distortions in the first-shell oxygen distribution involving long, 2.8--3.2 {angstrom} cation-O distances that are similar to those found in the amorphous phase of zirconium. The cation-cation distributions are also found to be quite complicated (non-Gaussian) and element specific. The U-near neighbor distances are expanded relative to the Ce ions for which it substitutes, consistent with the larger size of the actinide, and the U-cation distribution is also more complicated. In terms of the effects of this substitution on the other cation sites, the local environment around Y is altered while the Zr and Er local environments remain unchanged. These results point out the importance of collective and correlated interactions between the different pairs of cations and the host lattice that are mediated by the local strain fields generated by the different cations. The presence of pair-specific couplings has not been commonly included in previous analyses and may have implications for the stabilization mechanisms of cubic zirconia.

  20. The special symplectic structure of binary cubics

    CERN Document Server

    Slupinski, Marcus

    2009-01-01

    Let $k$ be a field of characteristic not 2 or 3. Let $V$ be the $k$-space of binary cubic polynomials. The natural symplectic structure on $k^2$ promotes to a symplectic structure $\\omega$ on $V$ and from the natural symplectic action of $\\textrm{Sl}(2,k)$ one obtains the symplectic module $(V,\\omega)$. We give a complete analysis of this symplectic module from the point of view of the associated moment map, its norm square $Q$ (essentially the classical discriminant) and the symplectic gradient of $Q$. Among the results are a symplectic derivation of the Cardano-Tartaglia formulas for the roots of a cubic, detailed parameters for all $\\textrm{Sl}(2,k)$ and $\\textrm{Gl}(2,k)$-orbits, in particular identifying a group structure on the set of $\\textrm{Sl}(2,k)$-orbits of fixed nonzero discriminant, and a purely symplectic generalization of the classical Eisenstein syzygy for the covariants of a binary cubic. Such fine symplectic analysis is due to the special symplectic nature inherited from the ambient excepti...

  1. Method of synthesizing cubic system boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Yuzu, S.; Sumiya, H.; Degawa, J.

    1987-10-13

    A method is described for synthetically growing cubic system boron nitride crystals by using boron nitride sources, solvents for dissolving the boron nitride sources, and seed crystals under conditions of ultra-high pressure and high temperature for maintaining the cubic system boron nitride stable. The method comprises the following steps: preparing a synthesizing vessel having at least two chambers, arrayed in order in the synthesizing vessel so as to be heated according to a temperature gradient; placing the solvents having different eutectic temperatures in each chamber with respect to the boron nitride sources according to the temperature gradient; placing the boron nitride source in contact with a portion of each of the solvents heated at a relatively higher temperature and placing at least a seed crystal in a portion of each of the solvents heated at a relatively lower temperature; and growing at least one cubic system boron nitride crystal in each of the solvents in the chambers by heating the synthesizing vessel for establishing the temperature gradient while maintaining conditions of ultra-high pressure and high temperature.

  2. Telerobot task planning and reasoning: Introduction to JPL artificial intelligence research

    Science.gov (United States)

    Atkinson, D. J.

    1987-01-01

    A view of the capabilities and areas of artificial intelligence research which are required for autonomous space telerobotics extending through the year 2000 is given. In the coming years, JPL will be conducting directed research to achieve these capabilities, as well as drawing heavily on collaborative efforts conducted with other research laboratories.

  3. Analysis of Drift Errors in the JPL/UCLA Micromachined Gyroscope

    Science.gov (United States)

    Chakraborty, I.

    1996-01-01

    The model of the JPL/UCLA micromachined vibratory gyroscope will be enhanced to include time varying effects. First, they will be shown to exist through trends in the experimental results. Causes of mechanical error will be further explained by analyzing possible perturbations to the physical model.

  4. Missions to Mars: MSL and Mars 2020; interview with AE alumnus Gerhard Kruizinga working at JPL

    NARCIS (Netherlands)

    Wink, J.; Roos, B.; Gupta, S.

    2013-01-01

    The Jet Propulsion Laboratory (JPL) located in Pasadena, California is the leading organisation for planetary missions and a point of attraction for many Aerospace Engineers. The Leonardo Times interviewed a former student of our faculty who made the big leap overseas and dedicated his career to pla

  5. The software product assurance metrics study: JPL's software systems quality and productivity

    Science.gov (United States)

    Bush, Marilyn W.

    1989-01-01

    The findings are reported of the Jet Propulsion Laboratory (JPL)/Software Product Assurance (SPA) Metrics Study, conducted as part of a larger JPL effort to improve software quality and productivity. Until recently, no comprehensive data had been assembled on how JPL manages and develops software-intensive systems. The first objective was to collect data on software development from as many projects and for as many years as possible. Results from five projects are discussed. These results reflect 15 years of JPL software development, representing over 100 data points (systems and subsystems), over a third of a billion dollars, over four million lines of code and 28,000 person months. Analysis of this data provides a benchmark for gauging the effectiveness of past, present and future software development work. In addition, the study is meant to encourage projects to record existing metrics data and to gather future data. The SPA long term goal is to integrate the collection of historical data and ongoing project data with future project estimations.

  6. Space Missions Trade Space Generation and Assessment Using JPL Rapid Mission Architecture (RMA) Team Approach

    Science.gov (United States)

    Moeller, Robert C.; Borden, Chester; Spilker, Thomas; Smythe, William; Lock, Robert

    2011-01-01

    The JPL Rapid Mission Architecture (RMA) capability is a novel collaborative team-based approach to generate new mission architectures, explore broad trade space options, and conduct architecture-level analyses. RMA studies address feasibility and identify best candidates to proceed to further detailed design studies. Development of RMA first began at JPL in 2007 and has evolved to address the need for rapid, effective early mission architectural development and trade space exploration as a precursor to traditional point design evaluations. The RMA approach integrates a small team of architecture-level experts (typically 6-10 people) to generate and explore a wide-ranging trade space of mission architectures driven by the mission science (or technology) objectives. Group brainstorming and trade space analyses are conducted at a higher level of assessment across multiple mission architectures and systems to enable rapid assessment of a set of diverse, innovative concepts. This paper describes the overall JPL RMA team, process, and high-level approach. Some illustrative results from previous JPL RMA studies are discussed.

  7. Data communication between data terminal equipment and the JPL administrative data base management system

    Science.gov (United States)

    Iverson, R. W.

    1984-01-01

    Approaches to enabling an installed base of mixed data terminal equipment to access a data base management system designed to work with a specific terminal are discussed. The approach taken by the Jet Propulsion Laboratory is described. Background information on the Jet Propulsion Laboratory (JPL), its organization and a description of the Administrative Data Base Management System is included.

  8. Compliant Biped Walking on Uneven Terrain with Point Feet

    Directory of Open Access Journals (Sweden)

    Wenqi Hou

    2016-03-01

    Full Text Available In this paper, we aim to realize compliant biped walking on uneven terrain with point feet. A control system is designed for a 5-link planar biped walker. According to the role that each leg plays, the control system is decomposed into two parts: the swing leg control and the support leg control. The trajectory of the swing foot is generated in realtime to regulate the walking speed. By considering the reaction torque of the swing leg’s hip joint as disturbance, a sliding model controller is implemented at the support leg’s hip joint to control the torso’s posture angle. In order to make sure the landing foot does not rebound after impact, the vertical contact force control is set as the internal loop of the hip’s height control. In simulation, the control system is tested on a virtual 5-link planar biped walker in Matlab. Finally, stable biped walking is realized on uneven terrain with roughness up to 2cm.

  9. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

    2015-01-15

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  10. Accessory bones of the feet: Radiological analysis of frequency

    Directory of Open Access Journals (Sweden)

    Vasiljević Vladica

    2010-01-01

    Full Text Available Background/Aim. Accessory bones are most commonly found on the feet and they represent an anatomic variant. They occur when there is a failure in the formation of a unique bone from separated centre of ossification. The aim of this study was to establish their frequency and medical significance. Methods. Anteroposterior and lateral foot radiography was performed in 270 patients aged of 20-80 years with a history of trauma (180 and rheumatology disease (90. The presence and distribution of accessory bones was analysed in relation to the total number of patients and their gender. The results are expressed in numeric values and in terms of percentage. Results. Accessory bones were identified in 62 (22.96% patients: 29 (10.74% of them were found in female patients and 33 (12.22% in males. The most common accessory bones were as follows: os tibiale externum 50%, os peroneum 29.03%, ostrigonum 11.29%, os vaselianum 9.68%. Conclusion. Accessory bones found in 23% of patients with trauma and some of rheumatological diseases. Their significance is demonstrated in the differential diagnosis among degenerative diseases, avulsion fractures, muscle and tendon trauma and other types of injuries which can cause painful affection of the foot, as well as in forensic practice.

  11. Cherenkov and Scintillation Properties of Cubic Zirconium

    Science.gov (United States)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  12. Tachyon Vacuum in Cubic Superstring Field Theory

    CERN Document Server

    Erler, Theodore

    2008-01-01

    In this paper we give an exact analytic solution for tachyon condensation in the modified (picture 0) cubic superstring field theory. We prove the absence of cohomology and, crucially, reproduce the correct value for the D-brane tension. The solution is surprising for two reasons: First, the existence of a tachyon vacuum in this theory has not been definitively established in the level expansion. Second, the solution {\\it vanishes} in the GSO$(-)$ sector, implying a ``tachyon vacuum'' solution exists even for a {\\it BPS} D-brane.

  13. Generalized fairing algorithm of parametric cubic splines

    Institute of Scientific and Technical Information of China (English)

    WANG Yuan-jun; CAO Yuan

    2006-01-01

    Kjellander has reported an algorithm for fairing uniform parametric cubic splines. Poliakoff extended Kjellander's algorithm to non-uniform case. However, they merely changed the bad point's position, and neglected the smoothing of tangent at bad point. In this paper, we present a fairing algorithm that both changed point's position and its corresponding tangent vector. The new algorithm possesses the minimum property of energy. We also proved Poliakoff's fairing algorithm is a deduction of our fairing algorithm. Several fairing examples are given in this paper.

  14. Fractal Symmetries: Ungauging the Cubic Code

    CERN Document Server

    Williamson, Dominic J

    2016-01-01

    Gauging is a ubiquitous tool in many-body physics. It allows one to construct highly entangled topological phases of matter from relatively simple phases and to relate certain characteristics of the two. Here we develop a gauging procedure for general submanifold symmetries of Pauli Hamiltonians, including symmetries of fractal type. We show a relation between the pre- and post- gauging models and use this to construct short range entangled phases with fractal like symmetries, one of which is mapped to the cubic code by the gauging.

  15. The Exact Limit of Some Cubic Towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Beelen, Peter; Nguyen, Nhut

    2016-01-01

    Recently, a new explicit tower of function fields was introduced by Bassa, Beelen, Garcia and Stichtenoth (BBGS). This resulted in currently the best known lower bound for Ihara’s constant in the case of non-prime finite fields. In particular over cubic fields, the tower’s limit is at least as good...... as Zink’s bound; i.e. λ(BBGS/Fq3 ) ≥ 2(q2 - 1)/(q + 2). In this paper, the exact value of λ(BBGS/Fq3 ) is computed. We also settle a question stated by Ihara....

  16. Competing structural instabilities in cubic perovskites

    CERN Document Server

    Vanderbilt, D

    1994-01-01

    We study the antiferrodistortive instability and its interaction with ferroelectricity in cubic perovskite compounds. Our first-principles calculations show that coexistence of both instabilities is very common. We develop a first-principles scheme to study the thermodynamics of these compounds when both instabilities are present, and apply it to SrTiO$_3$. We find that increased pressure enhances the antiferrodistortive instability while suppressing the ferroelectric one. Moreover, the presence of one instability tends to suppress the other. A very rich $P$--$T$ phase diagram results.

  17. Rheological properties of Cubic colloidal suspensions

    Science.gov (United States)

    Boromand, Arman; Maia, Joao

    2016-11-01

    Colloidal and non-colloidal suspensions are ubiquitous in many industrial application. There are numerous studies on these systems to understand and relate their complex rheological properties to their microstructural evolution under deformation. Although most of the experimental and simulation studies are centered on spherical particles, in most of the industrial applications the geometry of the colloidal particles deviate from the simple hard sphere and more complex geometries exist. Recent advances in microfabrication paved the way to fabricate colloidal particles with complex geometries for applications in different areas such as drug delivery where the fundamental understanding of their dynamics has remained unexplored. In this study, using dissipative particle dynamics, we investigate the rheological properties of cubic (superball) particles which are modeled as the cluster of core-modified DPD particles. Explicit representation of solvent particles in the DPD scheme will conserve the full hydrodynamic interactions between colloidal particles. Rheological properties of these cubic suspensions are investigated in the dilute and semi-dilute regimes. The Einstein and Huggins coefficients for these particles with different superball exponent will be calculate which represent the effect of single particle's geometry and multibody interactions on viscosity, respectively. The response of these suspensions is investigated under simple shear and oscillatory shear where it is shown that under oscillation these particles tend to form crystalline structure giving rise to stronger shear-thinning behavior recently measured experimentally.

  18. Forest Structure Characterization Using Jpl's UAVSAR Multi-Baseline Polarimetric SAR Interferometry and Tomography

    Science.gov (United States)

    Neumann, Maxim; Hensley, Scott; Lavalle, Marco; Ahmed, Razi

    2013-01-01

    This paper concerns forest remote sensing using JPL's multi-baseline polarimetric interferometric UAVSAR data. It presents exemplary results and analyzes the possibilities and limitations of using SAR Tomography and Polarimetric SAR Interferometry (PolInSAR) techniques for the estimation of forest structure. Performance and error indicators for the applicability and reliability of the used multi-baseline (MB) multi-temporal (MT) PolInSAR random volume over ground (RVoG) model are discussed. Experimental results are presented based on JPL's L-band repeat-pass polarimetric interferometric UAVSAR data over temperate and tropical forest biomes in the Harvard Forest, Massachusetts, and in the La Amistad Park, Panama and Costa Rica. The results are partially compared with ground field measurements and with air-borne LVIS lidar data.

  19. Performance capabilities of a JPL dual-arm advanced teleoperation system

    Science.gov (United States)

    Szakaly, Z. F.; Bejczy, A. K.

    1991-01-01

    The system comprises: (1) two PUMA 560 robot arms, each equipped with the latest JPL developed smart hands which contain 3-D force/moment and grasp force sensors; (2) two general purpose force reflecting hand controllers; (3) a NS32016 microprocessors based distributed computing system together with JPL developed universal motor controllers; (4) graphics display of sensor data; (5) capabilities for time delay experiments; and (6) automatic data recording capabilities. Several different types of control modes are implemented on this system using different feedback control techniques. Some of the control modes and the related feedback control techniques are described, and the achievable control performance for tracking position and force trajectories are reported. The interaction between position and force trajectory tracking is illustrated. The best performance is obtained by using a novel, task space error feedback technique.

  20. Forest Structure Characterization Using Jpl's UAVSAR Multi-Baseline Polarimetric SAR Interferometry and Tomography

    Science.gov (United States)

    Neumann, Maxim; Hensley, Scott; Lavalle, Marco; Ahmed, Razi

    2013-01-01

    This paper concerns forest remote sensing using JPL's multi-baseline polarimetric interferometric UAVSAR data. It presents exemplary results and analyzes the possibilities and limitations of using SAR Tomography and Polarimetric SAR Interferometry (PolInSAR) techniques for the estimation of forest structure. Performance and error indicators for the applicability and reliability of the used multi-baseline (MB) multi-temporal (MT) PolInSAR random volume over ground (RVoG) model are discussed. Experimental results are presented based on JPL's L-band repeat-pass polarimetric interferometric UAVSAR data over temperate and tropical forest biomes in the Harvard Forest, Massachusetts, and in the La Amistad Park, Panama and Costa Rica. The results are partially compared with ground field measurements and with air-borne LVIS lidar data.

  1. Commercialization of JPL Virtual Reality calibration and redundant manipulator control technologies

    Science.gov (United States)

    Kim, Won S.; Seraji, Homayoun; Fiorini, Paolo; Brown, Robert; Christensen, Brian; Beale, Chris; Karlen, James; Eismann, Paul

    1994-01-01

    Within NASA's recent thrust for industrial collaboration, JPL (Jet Propulsion Laboratory) has recently established two technology cooperation agreements in the robotics area: one on virtual reality (VR) calibration with Deneb Robotics, Inc., and the other on redundant manipulator control with Robotics Research Corporation (RRC). These technology transfer cooperation tasks will enable both Deneb and RRC to commercialize enhanced versions of their products that will greatly benefit both space and terrestrial telerobotic applications.

  2. New mode switching algorithm for the JPL 70-meter antenna servo controller

    Science.gov (United States)

    Nickerson, J. A.

    1988-01-01

    The design of control mode switching algorithms and logic for JPL's 70 m antenna servo controller are described. The old control mode switching logic was reviewed and perturbation problems were identified. Design approaches for mode switching are presented and the final design is described. Simulations used to compare old and new mode switching algorithms and logic show that the new mode switching techniques will significantly reduce perturbation problems.

  3. All unitary cubic curvature gravities in D dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Sisman, Tahsin Cagri; Guellue, Ibrahim; Tekin, Bayram, E-mail: sisman@metu.edu.tr, E-mail: e075555@metu.edu.tr, E-mail: btekin@metu.edu.tr [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey)

    2011-10-07

    We construct all the unitary cubic curvature gravity theories built on the contractions of the Riemann tensor in D-dimensional (anti)-de Sitter spacetimes. Our construction is based on finding the equivalent quadratic action for the general cubic curvature theory and imposing ghost and tachyon freedom, which greatly simplifies the highly complicated problem of finding the propagator of cubic curvature theories in constant curvature backgrounds. To carry out the procedure we have also classified all the unitary quadratic models. We use our general results to study the recently found cubic curvature theories using different techniques and the string generated cubic curvature gravity model. We also study the scattering in critical gravity and give its cubic curvature extensions.

  4. Experiences with Text Mining Large Collections of Unstructured Systems Development Artifacts at JPL

    Science.gov (United States)

    Port, Dan; Nikora, Allen; Hihn, Jairus; Huang, LiGuo

    2011-01-01

    Often repositories of systems engineering artifacts at NASA's Jet Propulsion Laboratory (JPL) are so large and poorly structured that they have outgrown our capability to effectively manually process their contents to extract useful information. Sophisticated text mining methods and tools seem a quick, low-effort approach to automating our limited manual efforts. Our experiences of exploring such methods mainly in three areas including historical risk analysis, defect identification based on requirements analysis, and over-time analysis of system anomalies at JPL, have shown that obtaining useful results requires substantial unanticipated efforts - from preprocessing the data to transforming the output for practical applications. We have not observed any quick 'wins' or realized benefit from short-term effort avoidance through automation in this area. Surprisingly we have realized a number of unexpected long-term benefits from the process of applying text mining to our repositories. This paper elaborates some of these benefits and our important lessons learned from the process of preparing and applying text mining to large unstructured system artifacts at JPL aiming to benefit future TM applications in similar problem domains and also in hope for being extended to broader areas of applications.

  5. Experiences with Text Mining Large Collections of Unstructured Systems Development Artifacts at JPL

    Science.gov (United States)

    Port, Dan; Nikora, Allen; Hihn, Jairus; Huang, LiGuo

    2011-01-01

    Often repositories of systems engineering artifacts at NASA's Jet Propulsion Laboratory (JPL) are so large and poorly structured that they have outgrown our capability to effectively manually process their contents to extract useful information. Sophisticated text mining methods and tools seem a quick, low-effort approach to automating our limited manual efforts. Our experiences of exploring such methods mainly in three areas including historical risk analysis, defect identification based on requirements analysis, and over-time analysis of system anomalies at JPL, have shown that obtaining useful results requires substantial unanticipated efforts - from preprocessing the data to transforming the output for practical applications. We have not observed any quick 'wins' or realized benefit from short-term effort avoidance through automation in this area. Surprisingly we have realized a number of unexpected long-term benefits from the process of applying text mining to our repositories. This paper elaborates some of these benefits and our important lessons learned from the process of preparing and applying text mining to large unstructured system artifacts at JPL aiming to benefit future TM applications in similar problem domains and also in hope for being extended to broader areas of applications.

  6. Cubic meter volume optical coherence tomography

    Science.gov (United States)

    WANG, ZHAO; POTSAID, BENJAMIN; CHEN, LONG; DOERR, CHRIS; LEE, HSIANG-CHIEH; NIELSON, TORBEN; JAYARAMAN, VIJAYSEKHAR; CABLE, ALEX E.; SWANSON, ERIC; FUJIMOTO, JAMES G.

    2017-01-01

    Optical coherence tomography (OCT) is a powerful three-dimensional (3D) imaging modality with micrometer-scale axial resolution and up to multi-GigaVoxel/s imaging speed. However, the imaging range of high-speed OCT has been limited. Here, we report 3D OCT over cubic meter volumes using a long coherence length, 1310 nm vertical-cavity surface-emitting laser and silicon photonic integrated circuit dual-quadrature receiver technology combined with enhanced signal processing. We achieved 15 µm depth resolution for tomographic imaging at a 100 kHz axial scan rate over a 1.5 m range. We show 3D macroscopic imaging examples of a human mannequin, bicycle, machine shop gauge blocks, and a human skull/brain model. High-bandwidth, meter-range OCT demonstrates new capabilities that promise to enable a wide range of biomedical, scientific, industrial, and research applications. PMID:28239628

  7. Black holes in Einsteinian cubic gravity

    CERN Document Server

    Hennigar, Robie A

    2016-01-01

    Using numerical and perturbative methods, we construct the first examples of black hole solutions in Einsteinian cubic gravity and study their thermodynamics. Focusing first on four dimensional solutions, we show that these black holes have a novel equation of state in which the pressure is a quadratic function of the temperature. Despite this, they undergo a first order phase transition with associated van der Waals behaviour. We then construct perturbative solutions for general $D \\ge 5$ and study the properties of these solutions for $D=5$ and $D=6$ in particular. We find novel examples of zeroth order phase transitions and find super-entropic behaviour over a large portion of the parameter space. We analyse the specific heat, determining that the black holes are thermodynamically stable over large regions of parameter space.

  8. Triangulation of cubic panorama for view synthesis.

    Science.gov (United States)

    Zhang, Chunxiao; Zhao, Yan; Wu, Falin

    2011-08-01

    An unstructured triangulation approach, new to our knowledge, is proposed to apply triangular meshes for representing and rendering a scene on a cubic panorama (CP). It sophisticatedly converts a complicated three-dimensional triangulation into a simple three-step triangulation. First, a two-dimensional Delaunay triangulation is individually carried out on each face. Second, an improved polygonal triangulation is implemented in the intermediate regions of each of two faces. Third, a cobweblike triangulation is designed for the remaining intermediate regions after unfolding four faces to the top/bottom face. Since the last two steps well solve the boundary problem arising from cube edges, the triangulation with irregular-distribution feature points is implemented in a CP as a whole. The triangular meshes can be warped from multiple reference CPs onto an arbitrary viewpoint by face-to-face homography transformations. The experiments indicate that the proposed triangulation approach provides a good modeling for the scene with photorealistic rendered CPs.

  9. Black holes in a cubic Galileon universe

    CERN Document Server

    Babichev, Eugeny; Lehébel, Antoine; Moskalets, Tetiana

    2016-01-01

    We find and study the properties of black hole solutions for a subclass of Horndeski theory including the cubic Galileon term. The theory under study has shift symmetry but not reflection symmetry for the scalar field. The Galileon is assumed to have linear time dependence characterized by a velocity parameter. We give analytic 3-dimensional solutions that are akin to the BTZ solutions but with a non-trivial scalar field that modifies the effective cosmological constant. We then study the 4-dimensional asymptotically flat and de Sitter solutions. The latter present three different branches according to their effective cosmological constant. For two of these branches, we find families of black hole solutions, parametrized by the velocity of the scalar field. These spherically symmetric solutions, obtained numerically, are different from GR solutions close to the black hole event horizon, while they have the same de-Sitter asymptotic behavior. The velocity parameter represents black hole primary hair.

  10. Finite element differential forms on cubical meshes

    CERN Document Server

    Arnold, Douglas N

    2012-01-01

    We develop a family of finite element spaces of differential forms defined on cubical meshes in any number of dimensions. The family contains elements of all polynomial degrees and all form degrees. In two dimensions, these include the serendipity finite elements and the rectangular BDM elements. In three dimensions they include a recent generalization of the serendipity spaces, and new H(curl) and H(div) finite element spaces. Spaces in the family can be combined to give finite element subcomplexes of the de Rham complex which satisfy the basic hypotheses of the finite element exterior calculus, and hence can be used for stable discretization of a variety of problems. The construction and properties of the spaces are established in a uniform manner using finite element exterior calculus.

  11. Capturing dynamic cation hopping in cubic pyrochlores

    Science.gov (United States)

    Brooks Hinojosa, Beverly; Asthagiri, Aravind; Nino, Juan C.

    2011-08-01

    In direct contrast to recent reports, density functional theory predicts that the most stable structure of Bi2Ti2O7 pyrochlore is a cubic Fd3¯m space group by accounting for atomic displacements. The displaced Bi occupies the 96g(x,x,z) Wyckoff position with six equivalent sites, which create multiple local minima. Using nudged elastic band method, the transition states of Bi cation hopping between equivalent minima were investigated and an energy barrier between 0.11 and 0.21 eV was determined. Energy barriers associated with the motion of Bi between equivalent sites within the 96g Wyckoff position suggest the presence of dielectric relaxation in Bi2Ti2O7.

  12. On the plane-wave cubic vertex

    CERN Document Server

    Lucietti, J; Sinha, A K; Lucietti, James; Schäfer-Nameki, Sakura; Sinha, Aninda

    2004-01-01

    The exact bosonic Neumann matrices of the cubic vertex in plane-wave light-cone string field theory are derived using the contour integration techniques developed in our earlier paper. This simplifies the original derivation of the vertex. In particular, the Neumann matrices are written in terms of \\mu-deformed Gamma-functions, thus casting them into a form that elegantly generalizes the well-known flat-space solution. The asymptotics of the \\mu-deformed Gamma-functions allow one to determine the large-\\mu behaviour of the Neumann matrices including exponential corrections. We provide an explicit expression for the first exponential correction and make a conjecture for the subsequent exponential correction terms.

  13. Polarization conversion in cubic Raman crystals

    Science.gov (United States)

    McKay, Aaron; Sabella, Alexander; Mildren, Richard P.

    2017-01-01

    Nonlinear conversion of unpolarized beams to lower frequencies is generally inefficient in c(2) materials, as it is challenging to achieve phase-matching for input ordinary and extraordinary beams simultaneously in the normal dispersion regime. Here, we show that cubic Raman crystals having doubly and triply degenerate (E and F type) modes provide a method for efficient nonlinear frequency downconversion of an unpolarized beam and yield a linearly polarized output state. Using Mueller calculus, optimal crystal directions for such polarization conversion are determined. Using diamond, an example of an F-class Raman crystal, we have verified that such conversion is possible with near quantum-defect-limited slope efficiency and a linear polarization contrast of more than 23.9 dB. PMID:28169327

  14. On the Stability of Cubic Galileon Accretion

    CERN Document Server

    Bergliaffa, Santiago P E

    2016-01-01

    We examine the stability of steady-state galileon accretion for the case of a Schwarzshild black hole. Considering the galileon action up to the cubic term in a static and spherically symmetric background we obtain the general solution for the equation of motion which is divided in two branches. By perturbing this solution we define an effective metric which determines the propagation of fluctuations. In this general picture we establish the position of the sonic horizon together with the matching condition of the two branches on it. Restricting to the case of a Schwarzschild background, we show, via the analysis of the energy of the perturbations and its time derivative, that the accreting field is linearly stable.

  15. Low pressure growth of cubic boron nitride films

    Science.gov (United States)

    Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

    1997-01-01

    A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical vapor deposition. The cubic boron nitride film is useful as a substitute for diamond coatings for a variety of applications in which diamond is not suitable. any tetragonal or hexagonal boron nitride. The cubic boron nitride produced in accordance with the preceding example is particularly well-suited for use as a coating for ultra hard tool bits and abrasives, especially those intended to use in cutting or otherwise fabricating iron.

  16. Shape preserving rational cubic spline for positive and convex data

    Directory of Open Access Journals (Sweden)

    Malik Zawwar Hussain

    2011-11-01

    Full Text Available In this paper, the problem of shape preserving C2 rational cubic spline has been proposed. The shapes of the positive and convex data are under discussion of the proposed spline solutions. A C2 rational cubic function with two families of free parameters has been introduced to attain the C2 positive curves from positive data and C2 convex curves from convex data. Simple data dependent constraints are derived on free parameters in the description of rational cubic function to obtain the desired shape of the data. The rational cubic schemes have unique representations.

  17. Effect of Reaction Developing Training on Audio-Visual Feet Reaction Time in Wrestlers

    Science.gov (United States)

    Kaya, Mustafa

    2016-01-01

    Reaction time is one of the most determinative elements for a successful sports performance. The purpose of this study was to investigate the effect of 12-week feet reaction developing trainings upon feet reaction time of females at 11-13 age interval. Volunteer sportsmen between 11 and 13 age interval who were active in Tokat Provincial…

  18. Feet distance and static postural balance: implication on the role of natural stance.

    Science.gov (United States)

    Kim, Ji-Won; Kwon, Yuri; Jeon, Hyung-Min; Bang, Min-Jung; Jun, Jae-Hoon; Eom, Gwang-Moon; Lim, Do-Hyung

    2014-01-01

    The purpose of this study was to investigate 1) the effect of feet distance on static postural balance and 2) the location of natural feet distance and its possible role in the relationship of feet distance and postural balance. Static balance tests were performed on a force platform for 100 s with six different feet distances (0, 5, 10, 15, 20, 25 cm). Measures of postural balance included mean amplitude of horizontal ground reaction force (GRF) as well as the mean distance and velocity of the center of pressure (COP). All measures were discomposed into anterioposterior and mediolateral directions. ANOVA and post-hoc comparison were performed for all measures with feet distance as an independent factor. Also measured was the feet distance at the natural stance preferred by each subject. All measures significantly varied with feet distance (ppostural control) in an inverted pendulum model with the horizontal GRF ignored. On the other hand, horizontal GRF is the direct cause of horizontal acceleration of a center of mass. The present result on horizontal GRF shows that the effort of postural control is minimized around the feet distance of natural standing and implies why the natural stance is preferred.

  19. Energy storage and release of prosthetic feet Part 1: Biomechanical analysis related to user benefits

    NARCIS (Netherlands)

    Postema, K.; Hermens, H.J.; Vries, de J.; Koopman, H.F.J.M.; Eisma, W.H.

    1997-01-01

    The energy storing and releasing behaviour of 2 energy storing feet (ESF) and 2 conventional prosthetic feet (CF) were compared (ESF: Otto Bock Dynamic Pro and Hanger Quantum; CF: Otto Bock Multi Axial and Otto Bock Lager). Ten trans-tibial amputees were selected. The study was designed as a double-

  20. CRACK PROBLEM UNDER SHEAR LOADING IN CUBIC QUASICRYSTAL

    Institute of Scientific and Technical Information of China (English)

    周旺民; 范天佑; 尹姝媛

    2003-01-01

    The axisymmetric elasticity problem of cubic quasicrystal is reduced to a single higher-order partial differential equation by introducing a displacement function. Based on the work, the analytic solutions of elastic field of cubic quasicrystal with a penny-shaped crack under the shear loading are found, and the stress intensity factor and strain energy release rate are determined.

  1. Cubic Polynomials with Real or Complex Coefficients: The Full Picture

    Science.gov (United States)

    Bardell, Nicholas S.

    2016-01-01

    The cubic polynomial with real coefficients has a rich and interesting history primarily associated with the endeavours of great mathematicians like del Ferro, Tartaglia, Cardano or Vieta who sought a solution for the roots (Katz, 1998; see Chapter 12.3: The Solution of the Cubic Equation). Suffice it to say that since the times of renaissance…

  2. An application of Cubical Cohomology to Adinkras and Supersymmetry Representations

    CERN Document Server

    Doran, Charles; Landweber, Greg

    2012-01-01

    An Adinkra is a class of graphs with certain signs marking its vertices and edges, which encodes off-shell representations of the super Poincar\\'e algebra. The markings on the vertices and edges of an Adinkra are cochains for cubical cohomology. This article explores the cubical cohomology of Adinkras, treating these markings analogously to characteristic classes on smooth manifolds.

  3. Rational Cubics and Conics Representation: A Practical Approach

    Directory of Open Access Journals (Sweden)

    M. Sarfraz

    2012-08-01

    Full Text Available A rational cubic spline, with one family of shape parameters, has been discussed with the view to its application in Computer Graphics. It incorporates both conic sections and parametric cubic curves as special cases. The parameters (weights, in the description of the spline curve can be used to modify the shape of the curve, locally and globally, at the knot intervals. The rational cubic spline attains parametric   smoothness whereas the stitching of the conic segments preserves visually reasonable smoothness at the neighboring knots. The curve scheme is interpolatory and can plot parabolic, hyperbolic, elliptic, and circular splines independently as well as bits and pieces of a rational cubic spline.Key Words: Computer Graphics, Interpolation, Spline, Conic, Rational Cubic

  4. On cubic equations over $P-$adic field

    CERN Document Server

    Mukhamedov, Farrukh; Saburov, Mansoor

    2012-01-01

    We provide a solvability criteria for a depressed cubic equation in domains $\\bz_p^{*},\\bz_p,\\bq_p$. We show that, in principal, the Cardano method is not always applicable for such equations. Moreover, the numbers of solutions of the depressed cubic equation in domains $\\bz_p^{*},\\bz_p,\\bq_p$ are provided. Since $\\bbf_p\\subset\\bq_p,$ we generalize J.-P. Serre's \\cite{JPSJ} and Z.H.Sun's \\cite{ZHS1,ZHS3} results concerning with depressed cubic equations over the finite field $\\bbf_p$. Finally, all depressed cubic equations, for which the Cardano method could be applied, are described and the $p-$adic Cardano formula is provided for those cubic equations.

  5. A Pilot Study on Gait Kinematics of Old Women with Bound Feet

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2015-01-01

    Full Text Available Foot binding has a long and influential history in China. Little is known about biomechanical changes in gait caused by bound foot. The purpose of this study was to investigate the differences in lower limb kinematics between old women with bound feet and normal feet during walking. Six old women subjects (three with bound feet and three controls with normal feet volunteered to participate in this study. Video data were recorded with a high speed video camera and analysed in the SIMI motion analysis software. Compared to normal controls, bound feet subjects had faster gait cadence with shorter stride length as well as smaller ankle and knee range of motion (ROM. During preswing phase, ankle remained to be dorsiflexion for bound foot subjects. The data from bound foot group also demonstrated that toe vertical displacement increased continuously during whole swing phase without a minimum toe clearance (MTC. The findings indicate that older women with bound feet exhibit significant differences in gait pattern compared to those with normal feet, which is characterised by disappeared propulsion/push-off and reduced mobility of lower limb segments.

  6. The Body Center Cubic Quark Lattice Model

    CERN Document Server

    Lin Xu, Jiao

    2004-01-01

    The Standard Model while successful in many ways is incomplete; many questions remain. The origin of quark masses and hadronization of quarks are awaiting an answer. From the Dirac sea concept, we infer that two kinds of elementary quarks (u(0) and d(0)) constitute a body center cubic (BCC) quark lattice with a lattice constant a < $10^{-18}$m in the vacuum. Using energy band theory and the BCC quark lattice, we can deduce the rest masses and the intrinsic quantum numbers (I, S, C, b and Q) of quarks. With the quark spectrum, we deduce a baryon spectrum. The theoretical spectrum is in agreement well with the experimental results. Not only will this paper provide a physical basis for the Quark Model, but also it will open a door to study the more fundamental nature at distance scales <$10^{-18}$m. This paper predicts some new quarks $u_{c}$(6490) and d$_{b}$(9950), and new baryons $\\Lambda_{c}^{+}$(6500), $\\Lambda_{b}^{0}$(9960).

  7. An application of the IMC software to controller design for the JPL LSCL Experiment Facility

    Science.gov (United States)

    Zhu, Guoming; Skelton, Robert E.

    1993-01-01

    A software package which Integrates Model reduction and Controller design (The IMC software) is applied to design controllers for the JPL Large Spacecraft Control Laboratory Experiment Facility. Modal Cost Analysis is used for the model reduction, and various Output Covariance Constraints are guaranteed by the controller design. The main motivation is to find the controller with the 'best' performance with respect to output variances. Indeed it is shown that by iterating on the reduced order design model, the controller designed does have better performance than that obtained with the first model reduction.

  8. Geometric rectification and geocoding of JPL's AIRSAR data over hilly terrain

    Science.gov (United States)

    Degroof, H.; Degrandi, G.; Sieber, A. J.

    1991-01-01

    A post-processing system was developed to georeference and geocode airborne synthetic aperture radar (SAR) data collected by the JPL-Airborne SAR (AIRSAR) System over hilly terrain during the 1990 MAESTRO1 campaign. Georectification relates image coordinates and object coordinates while the geocoding involves resampling. The georectification method uses a hybrid method based upon a number of navigational parameters and minimal two ground-control points which are referenced in both image and map space. The calculation of the intersection of the SAR signal wavefront and a digital elevation model allowed, within certain error bounds, acquisition of the object-to-image and image-to-object relationships.

  9. Inertial Sensor-Based Two Feet Motion Tracking for Gait Analysis

    Directory of Open Access Journals (Sweden)

    Tran Nhat Hung

    2013-04-01

    Full Text Available Two feet motion is estimated for gait analysis. An inertial sensor is attached on each shoe and an inertial navigation algorithm is used to estimate the movement of both feet. To correct inter-shoe position error, a camera is installed on the right shoe and infrared LEDs are installed on the left shoe. The proposed system gives key gait analysis parameters such as step length, stride length, foot angle and walking speed. Also it gives three dimensional trajectories of two feet for gait analysis.

  10. Inertial sensor-based two feet motion tracking for gait analysis.

    Science.gov (United States)

    Hung, Tran Nhat; Suh, Young Soo

    2013-04-29

    Two feet motion is estimated for gait analysis. An inertial sensor is attached on each shoe and an inertial navigation algorithm is used to estimate the movement of both feet. To correct inter-shoe position error, a camera is installed on the right shoe and infrared LEDs are installed on the left shoe. The proposed system gives key gait analysis parameters such as step length, stride length, foot angle and walking speed. Also it gives three dimensional trajectories of two feet for gait analysis.

  11. Analysis of experience of feet functions perfection in rhythmic gymnastic exercises

    Directory of Open Access Journals (Sweden)

    Nesterova T.V.

    2009-10-01

    Full Text Available Trainers and gymnasts take the problem of the special preparation feet and developments of method of its perfection to the number of the actual. The results of the pedagogical testing are shown that basic (basic, pushed, amortisation and specific (aesthetic, manipulation, integral functions feet have a different degree of display. They will be realized in exercises on all of the stages of long-term preparation of sportswomen. Most dynamic perfection of functions feet gymnasts take place on the stages of initial and preliminary base preparation.

  12. Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

    DEFF Research Database (Denmark)

    Holstein, P; Lassen, N A

    1980-01-01

    The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... (SPPH) as measured with a photocell. Thirty-two patients (35 feet with ulcerations) had diabetes mellitus. The treatment was conservative. In 42 feet the ulcers healed after an average period of 5.8 months; in 24 feet major amputation became necessary after an average of 4.3 months. The frequency...

  13. Normal Values of Metatarsal Parabola Arch in Male and Female Feet

    Directory of Open Access Journals (Sweden)

    Gabriel Domínguez-Maldonado

    2014-01-01

    Full Text Available There is not any method to measure metatarsal protrusion in the whole metatarsal. The aim of this research is to know the normal metatarsal parabola in male and female feet. The system of measurement devised by Hardy and Clapham to evaluate the protrusion between metatarsals I and II was adapted to study the whole metatarsal parabola and applied to the five metatarsals of 169 normal feet, 72 female feet and 97 male feet. Authors measured all metatarsal protrusion relative to metatarsal II. The results obtained show a female metatarsal protrusion relative to metatarsal II of +1.27% for metatarsal I, -3.36% for metatarsal III, -8.34% for metatarsal IV, and -15.54% for metatarsal V. Data obtained for male metatarsal parabola were +0.5% for metatarsal I, -3.77 for metatarsal III, -9.57 for metatarsal IV, and -17.05 for metatarsal V. Differences between both metatarsal parabola were significant.

  14. Normal values of metatarsal parabola arch in male and female feet.

    Science.gov (United States)

    Domínguez-Maldonado, Gabriel; Munuera-Martinez, Pedro V; Castillo-López, José Manuel; Ramos-Ortega, Javier; Albornoz-Cabello, Manuel

    2014-01-01

    There is not any method to measure metatarsal protrusion in the whole metatarsal. The aim of this research is to know the normal metatarsal parabola in male and female feet. The system of measurement devised by Hardy and Clapham to evaluate the protrusion between metatarsals I and II was adapted to study the whole metatarsal parabola and applied to the five metatarsals of 169 normal feet, 72 female feet and 97 male feet. Authors measured all metatarsal protrusion relative to metatarsal II. The results obtained show a female metatarsal protrusion relative to metatarsal II of +1.27% for metatarsal I, -3.36% for metatarsal III, -8.34% for metatarsal IV, and -15.54% for metatarsal V. Data obtained for male metatarsal parabola were +0.5% for metatarsal I, -3.77 for metatarsal III, -9.57 for metatarsal IV, and -17.05 for metatarsal V. Differences between both metatarsal parabola were significant.

  15. Evaluation of caudal epidural anesthesia efficacy by measurement of feet skin temperature in children

    Directory of Open Access Journals (Sweden)

    M. Yu. Kurochkin

    2015-04-01

    Full Text Available Caudal epidural anesthesia in children is not performed in pure form, but only in combination with superficial general anesthesia. Therefore, a search for reliable evaluation criteria of the caudal epidural block onset in children remains actual. Aim. To evaluate effectiveness of caudal epidural anesthesia efficacy by measurement of feet skin temperature in children. Methods and results. We investigated feet skin temperature before the caudal blockade by bupivacaine and after 15–20 minutes in 30 children. The control group included 20 children who underwent total intravenous anesthesia. The study showed that feet skin temperature after caudal blockade significantly increased from 30,1±0,15°C to 33,0±0,1°C (10% and in the control group it did not change significantly. Conclusion. Thus, feet skin thermometry may be considered to be a reliable non-invasive method for assessing the onset of the caudal block.

  16. Foot deformation during walking: differences between static and dynamic 3D foot morphology in developing feet.

    Science.gov (United States)

    Barisch-Fritz, Bettina; Schmeltzpfenning, Timo; Plank, Clemens; Grau, Stefan

    2014-01-01

    The complex functions of feet require a specific composition, which is progressively achieved by developmental processes. This development should take place without being affected by footwear. The aim of this study is to evaluate differences between static and dynamic foot morphology in developing feet. Feet of 2554 participants (6-16 years) were recorded using a new scanner system (DynaScan4D). Each foot was recorded in static half and full weight-bearing and during walking. Several foot measures corresponding to those used in last construction were calculated. The differences were identified by one-way ANOVA and paired Student's t-test. Static and dynamic values of each foot measure must be considered to improve the fit of footwear. In particular, footwear must account for the increase of forefoot width and the decrease of midfoot girth. Furthermore, the toe box should have a more rounded shape. The findings are important for the construction of footwear for developing feet.

  17. JPL's GNSS Real-Time Earthquake and Tsunami (GREAT) Alert System

    Science.gov (United States)

    Bar-Sever, Yoaz; Miller, Mark; Vallisneri, Michele; Khachikyan, Robert; Meyer, Robert

    2017-04-01

    We describe recent developments to the GREAT Alert natural hazard monitoring service from JPL's Global Differential GPS (GDGPS) System. GREAT Alert provides real-time, 1 Hz positioning solutions for hundreds of GNSS tracking sites, from both global and regional networks, aiming to monitor ground motion in the immediate aftermath of earthquakes. We take advantage of the centralized data processing, which is collocated with the GNSS orbit determination operations of the GDGPS System, to combine orbit determination with large-scale point-positioning in a grand estimation scheme, and as a result realize significant improvement to the positioning accuracy compared to conventional stand-alone point positioning techniques. For example, the measured median site (over all sites) real-time horizontal positioning accuracy is 2 cm 1DRMS, and the median real-time vertical accuracy is 4 cm RMS. The GREAT Alert positioning service is integrated with automated global earthquake notices from the United States Geodetic Survey (USGS) to support near-real-time calculations of co-seismic displacements with attendant formal errors based both short-term and long-term error analysis for each individual site. We will show the millimeter-level resolution of co-seismic displacement can be achieved by this system. The co-seismic displacements, in turn, are fed into a JPL geodynamics and ocean models, that estimate the Earthquake magnitude and predict the potential tsunami scale.

  18. The JPL Electronic Nose: Monitoring Air in the US Lab on the International Space Station

    Science.gov (United States)

    Ryan, M. A.; Manatt, K. S.; Gluck, S.; Shevade, A. V.; Kisor, A. K.; Zhou, H.; Lara, L. M.; Homer, M. L.

    2010-01-01

    An electronic nose with a sensor array of 32 conductometric sensors has been developed at the Jet Propulsion Laboratory (JPL) to monitor breathing air in spacecraft habitat. The Third Generation ENose is designed to operate in the environment of the US Lab on the International Space Station (ISS). It detects a selected group of analytes at target concentrations in the ppm regime at an environmental temperature range of 18 - 30 oC, relative humidity from 25 - 75% and pressure from 530 to 760 torr. The monitoring targets are anomalous events such as leaks and spills of solvents, coolants or other fluids. The JPL ENose operated as a technology demonstration for seven months in the U.S. Laboratory Destiny during 2008-2009. Analysis of ENose monitoring data shows that there was regular, periodic rise and fall of humidity and occasional releases of Freon 218 (perfluoropropane), formaldehyde, methanol and ethanol. There were also several events of unknown origin, half of them from the same source. Each event lasted from 20 to 100 minutes, consistent with the air replacement time in the US Lab.

  19. Transit Time Distribution based on the ECCO-JPL Ocean Data Assimilation

    Science.gov (United States)

    Ito, Takamitsu; Wang, Ou

    2017-03-01

    Oceanic water mass is a mixture of waters with varying ages, and the Transit Time Distribution (TTD) measures its age spectrum. We construct a model-based TTD using the data-constrained circulation fields from the ECCO-JPL Ocean Data Assimilation, and test it against the observed and directly simulated distribution of pCFC-11 from the Pacific and Atlantic basins. The ECCO-JPL circulation provides overall reliable estimates of the upper ocean ventilation rates suitable for biogeochemical studies. Observed distributions of pCFC-11 in the upper ocean thermocline are well reproduced by the convolution integral of the model-based TTD (mean bias 0.87) but there are significant regional biases in particular near the base of the thermocline and in the deep water formation regions. The model underestimates the deep pCFC-11 (> 2000 m) in the North Atlantic and in the Southern Ocean. The ratio between the mean and the spread of the age spectrum (Γ/Δ) is close to unity (mean = 1.04, median = 0.99) in the ventilated thermocline of the Pacific basin but there are significant regional variations of the ratio.

  20. System identification and structural control on the JPL Phase B testbed

    Science.gov (United States)

    Chu, Cheng-Chih; Obrien, John F.; Lurie, Boris J.

    1993-02-01

    The primary objective of NASA's CSI program at JPL is to develop and demonstrate the CSI technology required to achieve high precision structural stability on large complex optical class spacecraft. The focus mission for this work is an orbiting interferometer telescope. Toward the realization of such a mission, a series of evolutionary testbed structures are being constructed. The JPL's CSI Phase B testbed is the second structure constructed in this series which is designed to study the pathlength control problem of the optical train of a stellar interferometer telescope mounted on a large flexible structure. A detailed description of this testbed can be found. This paper describes our efforts in the first phase of active structural control experiments of Phase B testbed using the active control approach where a single piezoelectric active member is used as an actuation device and the measurements include both colocated and noncolocated sensors. Our goal for this experiment is to demonstrate the feasibility of active structural control using both colocated and noncolocated measurements by means of successive control design and loop closing. More specifically, the colocated control loop was designed and closed first to provide good damping improvement over the frequency range of interest. The noncolocated controller was then designed with respect to a partially controlled structure to further improve the performance. Based on our approach, experimental closed-loop results have demonstrated significant performance improvement with excellent stability margins.

  1. Cubic B-spline curve approximation by curve unclamping

    OpenAIRE

    Chen, Xiao-Diao; Ma, Weiyin; Paul, Jean-Claude

    2010-01-01

    International audience; A new approach for cubic B-spline curve approximation is presented. The method produces an approximation cubic B-spline curve tangent to a given curve at a set of selected positions, called tangent points, in a piecewise manner starting from a seed segment. A heuristic method is provided to select the tangent points. The first segment of the approximation cubic B-spline curve can be obtained using an inner point interpolation method, least-squares method or geometric H...

  2. On q-power cycles in cubic graphs

    DEFF Research Database (Denmark)

    Bensmail, Julien

    2017-01-01

    In the context of a conjecture of Erdos and Gyárfás, we consider, for any q ≥ 2, the existence of q-power cycles (i.e. with length a power of q) in cubic graphs. We exhibit constructions showing that, for every q ≥ 3, there exist arbitrarily large cubic graphs with no q-power cycles. Concerning...... the remaining case q = 2 (which corresponds to the conjecture of Erdos and Gyárfás), we show that there exist arbitrarily large cubic graphs whose only 2-power cycles have length 4 only, or 8 only....

  3. On q-power cycles in cubic graphs

    DEFF Research Database (Denmark)

    Bensmail, Julien

    2016-01-01

    In the context of a conjecture of Erdos and Gyárfás, we consider, for any q ≥ 2, the existence of q-power cycles (i.e. with length a power of q) in cubic graphs. We exhibit constructions showing that, for every q ≥ 3, there exist arbitrarily large cubic graphs with no q-power cycles. Concerning...... the remaining case q = 2 (which corresponds to the conjecture of Erdos and Gyárfás), we show that there exist arbitrarily large cubic graphs whose only 2-power cycles have length 4 only, or 8 only....

  4. The compressibility of cubic white and orthorhombic, rhombohedral, and simple cubic black phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Simon M; Zaug, Joseph

    2010-03-10

    The effect of pressure on the crystal structure of white phosphorus has been studied up to 22.4 GPa. The ?alpha phase was found to transform into the alpha' phase at 0.87 +- 0.04 GPa with a volume change of 0.1 +- 0.3 cc/mol. A fit of a second order Birch- Murnaghan equation to the data gave Vo = 16.94 ? 0.08 cc/mol and Ko = 6.7 +- 0.5 GPa for the alpha phase and Vo = 16.4 +- 0.1 cc/mol and Ko = 9.1 +- 0.3 GPa for the alpha' phase. The alpha' phase was found to transform to the A17 phase of black phosphorus at 2.68 +- 0.34 GPa and then with increasing pressure to the A7 and then simple cubic phase of black phosphorus. A fit of a second order Birch-Murnaghan equation to our data combined with previous measurements gave Vo = 11.43 +- 0.05 cc/mol and Ko = 34.7 +- 0.5 GPa for the A17 phase, Vo = 9.62 +- 0.01 cc/mol and Ko = 65.0 +- 0.6 GPa for the A7 phase and , Vo = 9.23 +- 0.01 cc/mol and Ko = 72.5 +- 0.3 GPa for the simple cubic phase.

  5. Foot-mediated incubation: Nazca booby (Sula granti) feet as surrogate brood patches.

    Science.gov (United States)

    Morgan, Stephanie M; Ashley-Ross, Miriam A; Anderson, David J

    2003-01-01

    Incubation in most avian species involves transferring heat from parent to egg through a highly vascularized brood patch. Some birds, however, do not develop a brood patch. Unusual among birds, these species hold their eggs under the webs of their feet, but the role of the feet in heat transfer is uncertain. Often the webs are positioned between the feathered abdomen and the egg during incubation, suggesting that either the abdomen, the feet, or both could transfer heat to the egg. We studied heat transfer from foot webs to eggs during incubation in Nazca boobies by spatially separating the feet from the abdomen using an oversized egg. We found that feet transfer heat to eggs independently of any heat that may be transferred from the abdomen. In addition, we found that incubating boobies had significantly greater vascularization in their foot webs, measured as a percentage of web area covered by vessels, than nonincubating boobies. We also found that males, whether incubating or nonincubating, had significantly less web vascularization than females. We concluded that vascularized Nazca booby feet function in the same way during incubation that vascularized brood patches do, acting as surrogate brood patches.

  6. MACSIGMA0 - MACINTOSH TOOL FOR ANALYZING JPL AIRSAR, ERS-1, JERS-1, AND MAGELLAN MIDR DATA

    Science.gov (United States)

    Norikane, L.

    1994-01-01

    MacSigma0 is an interactive tool for the Macintosh which allows you to display and make computations from radar data collected by the following sensors: the JPL AIRSAR, ERS-1, JERS-1, and Magellan. The JPL AIRSAR system is a multi-polarimetric airborne synthetic aperture radar developed and operated by the Jet Propulsion Laboratory. It includes the single-frequency L-band sensor mounted on the NASA CV990 aircraft and its replacement, the multi-frequency P-, L-, and C-band sensors mounted on the NASA DC-8. MacSigma0 works with data in the standard JPL AIRSAR output product format, the compressed Stokes matrix format. ERS-1 and JERS-1 are single-frequency, single-polarization spaceborne synthetic aperture radars launched by the European Space Agency and NASDA respectively. To be usable by MacSigma0, The data must have been processed at the Alaska SAR Facility and must be in the "low-resolution" format. Magellan is a spacecraft mission to map the surface of Venus with imaging radar. The project is managed by the Jet Propulsion Laboratory. The spacecraft carries a single-frequency, single-polarization synthetic aperture radar. MacSigma0 works with framelets of the standard MIDR CD-ROM data products. MacSigma0 provides four basic functions: synthesis of images (if necessary), statistical analysis of selected areas, analysis of corner reflectors as a calibration measure (if appropriate and possible), and informative mouse tracking. For instance, the JPL AIRSAR data can be used to synthesize a variety of images such as a total power image. The total power image displays the sum of the polarized and unpolarized components of the backscatter for each pixel. Other images which can be synthesized are HH, HV, VV, RL, RR, HHVV*, HHHV*, HVVV*, HHVV* phase and correlation coefficient images. For the complex and phase images, phase is displayed using color and magnitude is displayed using intensity. MacSigma0 can also be used to compute statistics from within a selected area. The

  7. Global infinite energy solutions for the cubic wave equation

    OpenAIRE

    Burq, N.; L. Thomann; Tzvetkov, N.

    2012-01-01

    International audience; We prove the existence of infinite energy global solutions of the cubic wave equation in dimension greater than 3. The data is a typical element on the support of suitable probability measures.

  8. The Coulombic Lattice Potential of Ionic Compounds: The Cubic Perovskites.

    Science.gov (United States)

    Francisco, E.; And Others

    1988-01-01

    Presents coulombic models representing the particles of a system by point charges interacting through Coulomb's law to explain coulombic lattice potential. Uses rubidium manganese trifluoride as an example of cubic perovskite structure. Discusses the effects on cluster properties. (CW)

  9. Spinning solitons in cubic-quintic nonlinear media

    Indian Academy of Sciences (India)

    Lucian-Cornel Crasovan; Boris A Malomed; Dumitru Mihalache

    2001-11-01

    We review recent theoretical results concerning the existence, stability and unique features of families of bright vortex solitons (doughnuts, or ‘spinning’ solitons) in both conservative and dissipative cubic-quintic nonlinear media.

  10. Stress Intensity of Antiplane Conjugate Cracks in Cubic Quasicrystal

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei

    2008-01-01

    Based on the theory of Muskhelishvili, the general solutions for stress and strain of conjugate cracks in cubic quasicrystal are obtained, with which the stress intensity factors of cubic quasicrystal at crack tips and the stress distribution functions of phonon and phason fields are given. The results show that though phason field is coupled with phonon field by constitutive equations, the stress intensity factors are not coupled with any other factors.

  11. Optical studies of cubic III-nitride structures

    OpenAIRE

    Powell, Ross E L

    2014-01-01

    The properties of cubic nitrides grown by molecular beam epitaxy (MBE) on GaAs (001) have been studied using optical and electrical techniques. The aim of these studies was the improvement of the growth techniques in order to improve the quality of grown nitrides intended for bulk substrate and optoelectronic device applications. We have also characterised hexagonal nanocolumn structures incorporating indium. Firstly, bulk films of cubic AlxGa1-xN with aluminium fractions (x) spanning the ...

  12. An Analysis of Near Fields of 34m Antennas of JPL/NASA Deep Space Network

    Science.gov (United States)

    Jamnejad, Vahraz; Juan, Nuria Llombart

    2011-01-01

    This paper addresses the issue of calculating near fields of the 34m Beam Waveguide (BWG) antennas of the NASA/JPL Deep Space Network (DSN). Calculating the near fields of DSN antennas are of interest in receive mode where the transmitting signals from nearby flying objects such as helicopters and airplanes could interfere with the operation of sensitive RF receiving system of DSN antennas, and in the transmit mode where fields from high-powered DSN antennas interfere with receivers on nearby flying objects, as well as safety considerations for the operators and visitors to the grounds surrounding the antenna sites. A complete and detailed analysis has been performed using PO/PTD techniques, including surface errors and support struts effects. Some results are presented, including comparisons with preliminary field tests.

  13. Task-level testing of the JPL-OMV smart end effector

    Science.gov (United States)

    Hannaford, B.

    1987-01-01

    An intelligent end effector previously developed at JPL has been tested in over 21 hours of experimental teleoperation. The end effector provides local control of gripper clamping force and a 6-degree-of-freedom, wrist mounted force torque sensor. Resolved forces and torques were displayed to the test subjects, and the effect of this information on their performance of simulated satellite servicing tasks was assessed. The experienced subjects accomplished the tasks with lower levels of Remote Manipulator System (RMS) forces than intermediate and naive subjects, but the force levels were apparently uncorrelated with the presence or absence of the display. This negative finding was attributed to the lack of a suitable control mode in the manipulator control system.

  14. Spinor bose gases in cubic optical lattice

    Energy Technology Data Exchange (ETDEWEB)

    Mobarak, Mohamed Saidan Sayed Mohamed

    2014-01-27

    In recent years the quantum simulation of condensed-matter physics problems has resulted from exciting experimental progress in the realm of ultracold atoms and molecules in optical lattices. In this thesis we analyze theoretically a spinor Bose gas loaded into a three-dimensional cubic optical lattice. In order to account for different superfluid phases of spin-1 bosons with a linear Zeeman effect, we work out a Ginzburg-Landau theory for the underlying spin-1 Bose-Hubbard model. To this end we add artificial symmetry-breaking currents to the spin-1 Bose-Hubbard Hamiltonian in order to break the global U (1) symmetry. With this we determine a diagrammatic expansion of the grand-canonical free energy up to fourth order in the symmetry-breaking currents and up to the leading non-trivial order in the hopping strength which is of first order. As a cross-check we demonstrate that the resulting grand-canonical free energy allows to recover the mean-field theory. Applying a Legendre transformation to the grand-canonical free energy, where the symmetry-breaking currents are transformed to order parameters, we obtain the effective Ginzburg-Landau action. With this we calculate in detail at zero temperature the Mott insulator-superfluid quantum phase boundary as well as condensate and particle number density in the superfluid phase. We find that both mean-field and Ginzburg-Landau theory yield the same quantum phase transition between the Mott insulator and superfluid phases, but the range of validity of the mean-field theory turns out to be smaller than that of the Ginzburg-Landau theory. Due to this finding we expect that the Ginzburg-Landau theory gives better results for the superfluid phase and, thus, we restrict ourselves to extremize only the effective Ginzburg-Landau action with respect to the order parameters. Without external magnetic field the superfluid phase is a polar (ferromagnetic) state for anti-ferromagnetic (ferromagnetic) interactions, i.e. only the

  15. Multivariate analysis of GPS position time series of JPL second reprocessing campaign

    Science.gov (United States)

    Amiri-Simkooei, A. R.; Mohammadloo, T. H.; Argus, D. F.

    2017-01-01

    The second reprocessing of all GPS data gathered by the Analysis Centers of IGS was conducted in late 2013 using the latest models and methodologies. Improved models of antenna phase center variations and solar radiation pressure in JPL's reanalysis are expected to significantly reduce errors. In an earlier work, JPL estimates of position time series, termed first reprocessing campaign, were examined in terms of their spatial and temporal correlation, power spectra, and draconitic signal. Similar analyses are applied to GPS time series at 89 and 66 sites of the second reanalysis with the time span of 7 and 21 years, respectively, to study possible improvements. Our results indicate that the spatial correlations are reduced on average by a factor of 1.25. While the white and flicker noise amplitudes for all components are reduced by 29-56 %, the random walk amplitude is enlarged. The white, flicker, and random walk noise amount to rate errors of, respectively, 0.01, 0.12, and 0.09 mm/yr in the horizontal and 0.04, 0.41 and 0.3 mm/yr in the vertical. Signals reported previously, such as those with periods of 13.63, 14.76, 5.5, and 351.4 / n for n=1,2,ldots,8 days, are identified in multivariate spectra of both data sets. The oscillation of the draconitic signal is reduced by factors of 1.87, 1.87, and 1.68 in the east, north and up components, respectively. Two other signals with Chandlerian period and a period of 380 days can also be detected.

  16. JPL Technology Development for the Dark Ages Radio Explorer (DARE) Proposal

    Science.gov (United States)

    Jones, Dayton L.; Lazio, J.; Sanchez Barbetty, M.; Sigel, D.; O'Dwyer, I.

    2014-01-01

    In support of the Dark Ages Radio Explorer (DARE) proposal team, the Jet Propulsion Laboratory (JPL) has been investigating several technologies for this mission. The goal of DARE is to measure the sky-integrated spectrum of highly redshifted Hydrogen from the radio-quiet region above the far side of the Moon. The detailed shape of the spectrum in the 40-120 MHz region contains information on the epoch compact object formation and subsequent re-heating of the intergalactic medium. However, the expected Hydrogen signal strength is orders of magnitude weaker than the galactic foreground, and extreme instrumental stability and calibration accuracy will be needed to extract the signal of interest from the stronger foreground signal. JPL has developed a deployable bi-conical dipole antenna and measured its RF performance against a full-size, solid dipole to verify that the deployable concept will not compromise the spectral bandpass of the instrument. In addition, variations in bandpass response as a function of physical temperature of the front-end electronics (active balun and receiver) have been made over a wide temperature range. These data can be used to determine the required level of thermal control on the DARE spacecraft. This work has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We also acknowledge support from the Lunar University Network for Astrophysical Research (LUNAR). The LUNAR consortium has been funded by the NASA Lunar Science Institute to investigate concepts for astrophysical observatories on the Moon via cooperative agreement NNA09DB30A.

  17. Multivariate analysis of GPS position time series of JPL second reprocessing campaign

    Science.gov (United States)

    Amiri-Simkooei, A. R.; Mohammadloo, T. H.; Argus, D. F.

    2017-06-01

    The second reprocessing of all GPS data gathered by the Analysis Centers of IGS was conducted in late 2013 using the latest models and methodologies. Improved models of antenna phase center variations and solar radiation pressure in JPL's reanalysis are expected to significantly reduce errors. In an earlier work, JPL estimates of position time series, termed first reprocessing campaign, were examined in terms of their spatial and temporal correlation, power spectra, and draconitic signal. Similar analyses are applied to GPS time series at 89 and 66 sites of the second reanalysis with the time span of 7 and 21 years, respectively, to study possible improvements. Our results indicate that the spatial correlations are reduced on average by a factor of 1.25. While the white and flicker noise amplitudes for all components are reduced by 29-56 %, the random walk amplitude is enlarged. The white, flicker, and random walk noise amount to rate errors of, respectively, 0.01, 0.12, and 0.09 mm/yr in the horizontal and 0.04, 0.41 and 0.3 mm/yr in the vertical. Signals reported previously, such as those with periods of 13.63, 14.76, 5.5, and 351.4 / n for n=1,2,{\\ldots },8 days, are identified in multivariate spectra of both data sets. The oscillation of the draconitic signal is reduced by factors of 1.87, 1.87, and 1.68 in the east, north and up components, respectively. Two other signals with Chandlerian period and a period of 380 days can also be detected.

  18. Dorsal sensory impairment in hands and feet of people affected by Hansen's disease in Israel.

    Science.gov (United States)

    Wexler, Ruth; Melchior, Hanna

    2007-12-01

    Sensory testing in people affected by Hansen's disease is usually performed on palms and soles only. In Israel, both palmar/plantar and dorsal aspects of limbs are routinely tested. The aim of this study was to describe the magnitude of dorsal sensory impairment (SI) in limbs and compare the frequency of SI on palms and soles with that on the dorsum of hands and feet. In a cross-sectional study, limbs of 140 patients registered at The Israel Hansen's Disease Centre during the years 1999-2003 were tested for their sensory status. Both palmar/plantar and dorsal aspects were tested using Semmes-Weinstein monofilaments. SI was defined as not feeling stimuli applied with the 2 g monofilament. SI was detected on the dorsum in 43% of sites on hands and only in 27% on palms. 64% of sites on dorsum of feet had SI compared to 53% on the soles. SI was detected in up to 18% in hands with no palmar SI, and in 6% of feet with no plantar SI. Furthermore, SI on palms and soles was found to be accompanied by dorsal SI in all hands and in 97% of feet. SI on dorsum of limbs occurs more frequently than SI on palms and soles. Therefore sensory testing should also consider inclusion of the dorsal aspect of hands and feet.

  19. Terrain Adaptability Mechanism of Large Ruminants’ Feet on the Kinematics View

    Directory of Open Access Journals (Sweden)

    Qun Zhang

    2015-01-01

    Full Text Available Ruminants live in various parts of land. Similar cloven hooves assist ruminants in adapting to different ground environment during locomotion. This paper analyzes the general terrain adaptability of the feet of ruminants using kinematics of the equivalent mechanism model based on screw theory. Cloven hooves could adjust attitude by changing relative positions between two digits in swing phase. This function helps to choose better landing orientation. “Grasping” or “holding” a rock or other object on the ground passively provides extra adhesion force in stance phase. Ruminants could adjust the position of the metacarpophalangeal joint or metatarsophalangeal joint (MTP or MCP with no relative motion between the tip of feet and the ground, which ensures the adhesion and dexterity in stance phase. These functions are derived from an example from chamois’ feet and several assumptions, which are believed to demonstrate the foundation of adaptation of ruminants and ensure a stable and continuous movement.

  20. Terrain Adaptability Mechanism of Large Ruminants' Feet on the Kinematics View.

    Science.gov (United States)

    Zhang, Qun; Ding, Xilun; Xu, Kun

    2015-01-01

    Ruminants live in various parts of land. Similar cloven hooves assist ruminants in adapting to different ground environment during locomotion. This paper analyzes the general terrain adaptability of the feet of ruminants using kinematics of the equivalent mechanism model based on screw theory. Cloven hooves could adjust attitude by changing relative positions between two digits in swing phase. This function helps to choose better landing orientation. "Grasping" or "holding" a rock or other object on the ground passively provides extra adhesion force in stance phase. Ruminants could adjust the position of the metacarpophalangeal joint or metatarsophalangeal joint (MTP or MCP) with no relative motion between the tip of feet and the ground, which ensures the adhesion and dexterity in stance phase. These functions are derived from an example from chamois' feet and several assumptions, which are believed to demonstrate the foundation of adaptation of ruminants and ensure a stable and continuous movement.

  1. Flat feet

    Science.gov (United States)

    ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 674. Review Date 3/9/2017 Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David ...

  2. Why have not the hairs on the feet of gecko been smaller?

    Science.gov (United States)

    Su, Yewang; He, Shijie; Hwang, Keh-Chih; Ji, Baohua

    2012-10-01

    The nanometer size of the tiny hair is the key to the secret of strong stickiness of gecko's feet, by which the hair can achieve the maximum adhesion strength that is insensitive to the interfacial flaws with substrate surface. But the question why the hairs have not been smaller is not answered yet. In this study, we derived a geometric parameter of the surface structures considering lateral interaction among hairs, which gives a critical size below which these hairs will bunch together and cause failure of the adhesion, suggesting a lower limit of the dimension of hairs on gecko's feet.

  3. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    Directory of Open Access Journals (Sweden)

    Misner Bill D

    2007-07-01

    Full Text Available Abstract Background Athlete's Foot (Tinea pedis is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment. Methods A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1 after 48-hours feet enclosure, (2 after washing feet, and (3 after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil. Conclusion

  4. Effects of aluminum hinged shoes on the structure of contracted feet in Thoroughbred yearlings.

    Science.gov (United States)

    Tanaka, Kousuke; Hiraga, Atsushi; Takahashi, Toshiyuki; Kuwano, Atsutoshi; Morrison, Scott Edward

    2015-01-01

    We applied aluminum hinged shoes (AHSs) to the club foot-associated contracted feet of 11 Thoroughbred yearlings to examine the effects of the shoes on the shape of the hoof and third phalanx (P III). After 3 months of AHS use, the size of the affected hooves increased significantly, reaching the approximate size of the healthy contralateral hooves with respect to the maximum lateral width of the foot, the mean ratio of the bearing border width to the coronary band width, and the mean ratio of the solar surface width to the articular surface width. These results suggest that the AHSs corrected the contracted feet in these yearling horses.

  5. JPL Thermal Design Modeling Philosophy and NASA-STD-7009 Standard for Models and Simulations - A Case Study

    Science.gov (United States)

    Avila, Arturo

    2011-01-01

    The Standard JPL thermal engineering practice prescribes worst-case methodologies for design. In this process, environmental and key uncertain thermal parameters (e.g., thermal blanket performance, interface conductance, optical properties) are stacked in a worst case fashion to yield the most hot- or cold-biased temperature. Thus, these simulations would represent the upper and lower bounds. This, effectively, represents JPL thermal design margin philosophy. Uncertainty in the margins and the absolute temperatures is usually estimated by sensitivity analyses and/or by comparing the worst-case results with "expected" results. Applicability of the analytical model for specific design purposes along with any temperature requirement violations are documented in peer and project design review material. In 2008, NASA released NASA-STD-7009, Standard for Models and Simulations. The scope of this standard covers the development and maintenance of models, the operation of simulations, the analysis of the results, training, recommended practices, the assessment of the Modeling and Simulation (M&S) credibility, and the reporting of the M&S results. The Mars Exploration Rover (MER) project thermal control system M&S activity was chosen as a case study determining whether JPL practice is in line with the standard and to identify areas of non-compliance. This paper summarizes the results and makes recommendations regarding the application of this standard to JPL thermal M&S practices.

  6. Draft Genome Sequence of Bacillus safensis JPL-MERTA-8-2, Isolated from a Mars-Bound Spacecraft.

    Science.gov (United States)

    Coil, David A; Benardini, James N; Eisen, Jonathan A

    2015-11-19

    Here, we present the draft genome of Bacillus safensis JPL-MERTA-8-2, a strain found in a spacecraft assembly cleanroom before launch of the Mars Exploration Rovers. The assembly contains 3,671,133 bp in 14 contigs.

  7. Draft Genome Sequence of Bacillus safensis JPL-MERTA-8-2, Isolated from a Mars-Bound Spacecraft

    Science.gov (United States)

    Coil, David A.; Benardini, James N.

    2015-01-01

    Here, we present the draft genome of Bacillus safensis JPL-MERTA-8-2, a strain found in a spacecraft assembly cleanroom before launch of the Mars Exploration Rovers. The assembly contains 3,671,133 bp in 14 contigs. PMID:26586895

  8. To Mars and beyond; interview with Dr. Firouz Naderi, the director solar system exploration at NASA JPL

    NARCIS (Netherlands)

    Fattahyani, A.

    2013-01-01

    NASA’s Jet Propulsion Laboratory (JPL) is the leader of the planetary missions. Located in Pasadena, California, this laboratory is responsible for the operation of NASA’s planetary spacecraft and its deep space network. The Leonardo Times was able to have an interview with Dr. Firouz Naderi, who is

  9. To Mars and beyond; interview with Dr. Firouz Naderi, the director solar system exploration at NASA JPL

    NARCIS (Netherlands)

    Fattahyani, A.

    2013-01-01

    NASA’s Jet Propulsion Laboratory (JPL) is the leader of the planetary missions. Located in Pasadena, California, this laboratory is responsible for the operation of NASA’s planetary spacecraft and its deep space network. The Leonardo Times was able to have an interview with Dr. Firouz Naderi, who is

  10. A new hypercube variant: Fractal Cubic Network Graph

    Directory of Open Access Journals (Sweden)

    Ali Karci

    2015-03-01

    Full Text Available Hypercube is a popular and more attractive interconnection networks. The attractive properties of hypercube caused the derivation of more variants of hypercube. In this paper, we have proposed two variants of hypercube which was called as “Fractal Cubic Network Graphs”, and we have investigated the Hamiltonian-like properties of Fractal Cubic Network Graphs FCNGr(n. Firstly, Fractal Cubic Network Graphs FCNGr(n are defined by a fractal structure. Further, we show the construction and characteristics analyses of FCNGr(n where r=1 or r=2. Therefore, FCNGr(n is a Hamiltonian graph which is obtained by using Gray Code for r=2 and FCNG1(n is not a Hamiltonian Graph. Furthermore, we have obtained a recursive algorithm which is used to label the nodes of FCNG2(n. Finally, we get routing algorithms on FCNG2(n by utilizing routing algorithms on the hypercubes.

  11. Ferromagnetic Ground States in Face-Centered Cubic Hubbard Clusters

    Science.gov (United States)

    Souza, T. X. R.; Macedo, C. A.

    2016-01-01

    In this study, the ground state energies of face-centered cubic Hubbard clusters are analyzed using the Lanczos method. Examination of the ground state energy as a function of the number of particle per site n showed an energy minimum for face-centered cubic structures. This energy minimum decreased in n with increasing coulombic interaction parameter U. We found that the ground state energy had a minimum at n = 0.6, when U = 3W, where W denotes the non-interacting energy bandwidth and the face-centered cubic structure was ferromagnetic. These results, when compared with the properties of nickel, shows strong similarity with other finite temperature analyses in the literature and supports the Hirsh’s conjecture that the interatomic direct exchange interaction dominates in driving the system into a ferromagnetic phase. PMID:27583653

  12. Superconductivity in cubic noncentrosymmetric PdBiSe Crystal

    Science.gov (United States)

    Joshi, B.; Thamizhavel, A.; Ramakrishnan, S.

    2015-03-01

    Mixing of spin singlet and spin triplet superconducting pairing state is expected in noncentrosymmetric superconductors (NCS) due to the inherent presence of Rashba-type antisymmetric spin-orbit coupling. Unlike low symmetry (tetragonal or monoclinic) NCS, parity is isotropicaly broken in space for cubic NCS and can additionally lead to the coexistence of magnetic and superconducting state under certain conditions. Motivated with such enriched possibility of unconventional superconducting phases in cubic NCS we are reporting successful formation of single crystalline cubic noncentrosymmetric PdBiSe with lattice parameter a = 6.4316 Å and space group P21 3 (space group no. 198) which undergoes to superconducting transition state below 1.8 K as measured by electrical transport and AC susceptibility measurements. Significant strength of Rashba-type antisymmetric spin-orbit coupling can be expected for PdBiSe due to the presence of high Z (atomic number) elements consequently making it potential candidate for unconventional superconductivity.

  13. Cubic interactions of Maxwell-like higher spins

    CERN Document Server

    Francia, Dario; Mkrtchyan, Karapet

    2016-01-01

    We study the cubic vertices for Maxwell-like higher-spins in flat space. Reducibility of their free spectra implies that a single cubic vertex involving any three fields subsumes a number of couplings among different particles of various spins. The resulting vertices do not involve traces of the fields and in this sense are simpler than their Fronsdal counterparts. We propose an extension of both the free theory and of its cubic deformation to a more general class of partially reducible systems, that one can obtain from the original theory upon imposing trace constraints of various orders. The key to our results is a version of the Noether procedure allowing to systematically account for the deformations of the transversality conditions to be imposed on the gauge parameters at the free level.

  14. Extended temperature dependence of elastic constants in cubic crystals.

    Science.gov (United States)

    Telichko, A V; Sorokin, B P

    2015-08-01

    To extend the theory of the temperature dependence of the elastic constants in cubic crystals beyond the second- and third-order elastic constants, the fourth-order elastic constants, as well as the non-linearity in the thermal expansion temperature dependence, have been taken into account. Theoretical results were represented as temperature functions of the effective elastic constants and compared with experimental data for a number of cubic crystals, such as alkali metal halides, and elements gold and silver. The relations obtained give a more accurate description of the experimental temperature dependences of second-order elastic constants for a number of cubic crystals, including deviations from linear behavior. A good agreement between theoretical estimates and experimental data has been observed.

  15. Tetragonal and cubic zirconia multilayered ceramic constructs created by EPD.

    Science.gov (United States)

    Mochales, Carolina; Frank, Stefan; Zehbe, Rolf; Traykova, Tania; Fleckenstein, Christine; Maerten, Anke; Fleck, Claudia; Mueller, Wolf-Dieter

    2013-02-14

    The interest in electrophoretic deposition (EPD) for nanomaterials and ceramics production has widely increased due to the versatility of this technique to effectively combine different materials in unique shapes and structures. We successfully established an EPD layering process with submicrometer sized powders of Y-TZP with different mol percentages of yttrium oxide (3 and 8%) and produced multilayers of alternating tetragonal and cubic phases with a clearly defined interface. The rationale behind the design of these multilayer constructs was to optimize the properties of the final ceramic by combining the high mechanical toughness of the tetragonal phase of zirconia together with the high ionic conductivity of its cubic phase. In this work, a preliminary study of the mechanical properties of these constructs proved the good mechanical integrity of the multilayered constructs obtained as well as crack deflection in the interface between tetragonal and cubic zirconia layers.

  16. Body-centered-cubic Ni and its magnetic properties.

    Science.gov (United States)

    Tian, C S; Qian, D; Wu, D; He, R H; Wu, Y Z; Tang, W X; Yin, L F; Shi, Y S; Dong, G S; Jin, X F; Jiang, X M; Liu, F Q; Qian, H J; Sun, K; Wang, L M; Rossi, G; Qiu, Z Q; Shi, J

    2005-04-08

    The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.

  17. Hardness and thermal stability of cubic silicon nitride

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Kragh, Flemming; Frost, D. J.

    2001-01-01

    The hardness and thermal stability of cubic spinel silicon nitride (c-Si3N4), synthesized under high-pressure and high-temperature conditions, have been studied by microindentation measurements, and x-ray powder diffraction and scanning electron microscopy, respectively The phase at ambient...... temperature has an average hardness of 35.31 GPa, slightly larger than SiO2 stishovite, which is often referred to as the third hardest material after diamond and cubic boron nitride. The cubic phase is stable up to 1673 K in air. At 1873 K, alpha -and beta -Si3N4 phases are observed, indicating a phase...... transformation sequence of c-to-alpha -to-beta -Si3N4 phases....

  18. JPL Table Mountain Facility Support of the Ground/Orbiter Lasercomm Demonstration

    Science.gov (United States)

    Gillam, S. D.; Young, J. W.; Sidwell, D. R.

    1996-01-01

    On 23 nights between October 30, 1995, and January 13, 1996, the JPL Table Mountain Facility (TMF) was the site of the ground stations of the Ground/Orbiter Lasercomm Demonstration (GOLD). These 0.6-m and 1.2-m telescopes acted as terminals in a bent-pipe optical communications link. This link went from the ground to an optical communications transceiver terminal on the Japanese Engineering Test Satellite (ETS-VI) and back to the ground. This article describes how the TMF supported this novel optical communications experiment. This experiment was a collaborative effort between JPL, NASA's Deep Space Network (DSN), the Japanese National Aeronautics and Space Development Agency (NASDA), and the Japanese Communications Research Laboratory (CRL), which operates the ETS-VI. The 0.6-m telescope, in the coude configuration, was used to uplink a 514-nm modulated laser to the transceiver on the ETS-VI communications satellite. The 1.2-m telescope, in the Cassegrain configuration, was used to detect an 830-nm diode laser signal downlinked from the ETS-VI terminal. The downlink was sent only if the uplink beam was detected. The uplink beam had to be kept within a box 5 arcsec on a side and centered on the position of the ETS-VI. This required that the 0.6-m telescope track the ETS-VI to a precision of ~2 arcsec. The 1.2-m telescope was required to track to a precision of 4{5 arcsec because the downlink detector had an aperture with a 13-arcsec-diameter field of view. This article describes how the above tracking performance was met by both telescopes. Equipment designed for the experiment at the transmitter and receiver stations, acquisition methods, and software developed to support this project are discussed, as are experiments performed to establish the suitability of the TMF telescopes for this demonstration. This article discusses upgrades to the TMF electrical power system needed to support GOLD; mechanical, optical, and servo-control aspects of the transmitter and

  19. Healthy Feet are Happy Feet

    Centers for Disease Control (CDC) Podcasts

    2007-10-05

    This podcast offers tips for people with diabetes on foot care to prevent complications, such as foot ulcers and amputation.  Created: 10/5/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 12/2/2007.

  20. Image interpolation by two-dimensional parametric cubic convolution.

    Science.gov (United States)

    Shi, Jiazheng; Reichenbach, Stephen E

    2006-07-01

    Cubic convolution is a popular method for image interpolation. Traditionally, the piecewise-cubic kernel has been derived in one dimension with one parameter and applied to two-dimensional (2-D) images in a separable fashion. However, images typically are statistically nonseparable, which motivates this investigation of nonseparable cubic convolution. This paper derives two new nonseparable, 2-D cubic-convolution kernels. The first kernel, with three parameters (designated 2D-3PCC), is the most general 2-D, piecewise-cubic interpolator defined on [-2, 2] x [-2, 2] with constraints for biaxial symmetry, diagonal (or 90 degrees rotational) symmetry, continuity, and smoothness. The second kernel, with five parameters (designated 2D-5PCC), relaxes the constraint of diagonal symmetry, based on the observation that many images have rotationally asymmetric statistical properties. This paper also develops a closed-form solution for determining the optimal parameter values for parametric cubic-convolution kernels with respect to ensembles of scenes characterized by autocorrelation (or power spectrum). This solution establishes a practical foundation for adaptive interpolation based on local autocorrelation estimates. Quantitative fidelity analyses and visual experiments indicate that these new methods can outperform several popular interpolation methods. An analysis of the error budgets for reconstruction error associated with blurring and aliasing illustrates that the methods improve interpolation fidelity for images with aliased components. For images with little or no aliasing, the methods yield results similar to other popular methods. Both 2D-3PCC and 2D-5PCC are low-order polynomials with small spatial support and so are easy to implement and efficient to apply.

  1. Higher-spin Interactions from CFT: The Complete Cubic Couplings

    CERN Document Server

    Sleight, Charlotte

    2016-01-01

    In this letter we provide a complete holographic reconstruction of the cubic couplings in the minimal bosonic higher-spin theory in AdS$_{d+1}$. For this purpose we also determine the OPE coefficients of all single-trace conserved currents in the $d$-dimensional free scalar $O\\left(N\\right)$ vector model, and compute the tree-level three-point Witten diagram amplitudes for a generic cubic interaction of higher-spin gauge fields in the metric-like formulation.

  2. Classifying Cubic Edge-Transitive Graphs of Order 8

    Indian Academy of Sciences (India)

    Mehdi Alaeiyan; M K Hosseinipoor

    2009-11-01

    A simple undirected graph is said to be semisymmetric if it is regular and edge-transitive but not vertex-transitive. Let be a prime. It was shown by Folkman (J. Combin. Theory 3(1967) 215--232) that a regular edge-transitive graph of order 2 or 22 is necessarily vertex-transitive. In this paper, an extension of his result in the case of cubic graphs is given. It is proved that, every cubic edge-transitive graph of order 8 is symmetric, and then all such graphs are classified.

  3. Possible form of multi-polar interaction in cubic lattice

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Osamu; Shiina, Ryousuke; Shiba, Hiroyuki

    2003-05-01

    The invariant form of interaction between multi-poles, including the octupole, is studied for the simple cubic (SC), body centered and face centered cubic lattices. The coupling terms can be arranged in a way similar to that of the hopping matrix between the LCAO's. A table for SC by Shiina et al. (J. Phys. Soc. Japan 66 (1997) 1741) is generalized for the general wave number case of the three types of lattice. Recent experimental result of TmTe is thereby analyzed. The development of the ferromagnetic moment below the anti-ferromagnetic transition under the anti-ferro quadrupolar order phase is discussed in this connection.

  4. Possible form of multi-polar interaction in cubic lattice

    Science.gov (United States)

    Sakai, Osamu; Shiina, Ryousuke; Shiba, Hiroyuki

    2003-05-01

    The invariant form of interaction between multi-poles, including the octupole, is studied for the simple cubic (SC), body centered and face centered cubic lattices. The coupling terms can be arranged in a way similar to that of the hopping matrix between the LCAO's. A table for SC by Shiina et al. (J. Phys. Soc. Japan 66 (1997) 1741) is generalized for the general wave number case of the three types of lattice. Recent experimental result of TmTe is thereby analyzed. The development of the ferromagnetic moment below the anti-ferromagnetic transition under the anti-ferro quadrupolar order phase is discussed in this connection.

  5. Counting perfect matchings of cubic graphs in the geometric dual

    CERN Document Server

    Jiménez, Andrea

    2010-01-01

    Lov\\'asz and Plummer conjectured, in the mid 1970's, that every cubic graph G with no cutedge has an exponential in |V(G)| number of perfect matchings. In this work we show that every cubic planar graph G whose geometric dual graph is a stack triangulation has at least 3 times the golden ratio to |V(G)|/72 distinct perfect matchings. Our work builds on a novel approach relating Lov\\'asz and Plummer's conjecture and the number of so called groundstates of the widely studied Ising model from statistical physics.

  6. Elastic interaction of point defects in crystals with cubic symmetry

    Science.gov (United States)

    Kuz'michev, S. V.; Kukushkin, S. A.; Osipov, A. V.

    2013-07-01

    The energy of elastic mechanical interaction between point defects in cubic crystals is analyzed numerically. The finite-element complex ANSYS is used to investigate the character of interaction between point defects depending on their location along the crystallographic directions , , and on the distance from the free boundary of the crystal. The numerical results are compared with the results of analytic computations of the energy of interaction between two point defects in an infinite anisotropic medium with cubic symmetry. The interaction between compressible and incompressible defects of general type is studied. Conditions for onset of elastic attraction between the defects, which leads to general relaxation of the crystal elastic energy, are obtained.

  7. Cubic surfaces and their invariants: Some memories of Raymond Stora

    Directory of Open Access Journals (Sweden)

    Michel Bauer

    2016-11-01

    I then turn to the study of the family of cubic surfaces. They depend on 20 parameters, and the action of the 15 parameter group SL4(C splits the family in orbits depending on 5 parameters. This takes us into the realm of (geometric invariant theory. I review briefly the classical theorems on the structure of the ring of polynomial invariants and illustrate its many facets by looking at a simple example, before turning to the already involved case of cubic surfaces. The invariant ring was described in the 19th century. I show how to retrieve this description via counting/generating functions and character formulae.

  8. Foot Placement Modification for a Biped Humanoid Robot with Narrow Feet

    Directory of Open Access Journals (Sweden)

    Kenji Hashimoto

    2014-01-01

    Full Text Available This paper describes a walking stabilization control for a biped humanoid robot with narrow feet. Most humanoid robots have larger feet than human beings to maintain their stability during walking. If robot’s feet are as narrow as humans, it is difficult to realize a stable walk by using conventional stabilization controls. The proposed control modifies a foot placement according to the robot's attitude angle. If a robot tends to fall down, a foot angle is modified about the roll axis so that a swing foot contacts the ground horizontally. And a foot-landing point is also changed laterally to inhibit the robot from falling to the outside. To reduce a foot-landing impact, a virtual compliance control is applied to the vertical axis and the roll and pitch axes of the foot. Verification of the proposed method is conducted through experiments with a biped humanoid robot WABIAN-2R. WABIAN-2R realized a knee-bended walking with 30 mm breadth feet. Moreover, WABIAN-2R mounted on a human-like foot mechanism mimicking a human's foot arch structure realized a stable walking with the knee-stretched, heel-contact, and toe-off motion.

  9. Evaluation of postural stability in patients wit unilateral vestibular hypofunction:effect of feet orientation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; KONG Wei-Jia; LENG Yang-ming

    2008-01-01

    To investigate effect of feet orientation on the evaluation of the postural stability in patients with unilateral vestibular hypofunction (UVH) by timed standing tests and static posturography (SPG). Methods 65 subjects with UVH and 92 healthy subjects regarded as control group took the posrural stability tests in four different stances including (1) standard Romberg test, (2) feet-apart stance test, (3) tandem and (4) unilateral standing tests. In each stance, the postural stability was measured in both eyes open (EO) and eyes closed(EC) conditions. The average time that subjects kept balance before falling in each test conditions was recorded by stopwatch as the timed result. In addition, the sway velocity (SV) of center of foot pressure in the upright stance during standard Romberg test and feet apart stance, regarded as postural stability, was also recorded as SPG. Results (1) The balance-maintain-ing time of the UVH group in tandem and unilateral standing with EO and EC was decreased (P 0.05). Conclusions The results suggest that the tandem and unilateral stance tests may provide additional information about the upright stance to the SPG measurement in patients with UVH. The effect of feet orientation on SPG measurements should be considered.

  10. DISABILITIES OF HANDS, FEET AND EYES IN NEWLY-DIAGNOSED LEPROSY PATIENTS IN EASTERN NEPAL

    NARCIS (Netherlands)

    SCHIPPER, A; LUBBERS, WJ; HOGEWEG, M; DESOLDENHOFF, R

    1994-01-01

    The objective of the study was to determine the magnitude of hand/feet/eye disabilities in newly diagnosed leprosy patients by examining all newly diagnosed leprosy patients who presented at the Eastern Leprosy Control Project (supported by The Netherlands Leprosy Relief Association), made up of a r

  11. DISABILITIES OF HANDS, FEET AND EYES IN NEWLY-DIAGNOSED LEPROSY PATIENTS IN EASTERN NEPAL

    NARCIS (Netherlands)

    SCHIPPER, A; LUBBERS, WJ; HOGEWEG, M; DESOLDENHOFF, R

    The objective of the study was to determine the magnitude of hand/feet/eye disabilities in newly diagnosed leprosy patients by examining all newly diagnosed leprosy patients who presented at the Eastern Leprosy Control Project (supported by The Netherlands Leprosy Relief Association), made up of a

  12. Case Report: 16-Year-Old Male with Autistic Disorder with Preoccupation with Female Feet

    Science.gov (United States)

    Early, Maureen C.; Erickson, Craig A.; Wink, Logan K.; McDougle, Christopher J.; Scott, Eric L.

    2012-01-01

    This paper highlights clinical challenges faced when diagnosing and then treating an individual presenting to a child and adolescent psychiatry clinic because of unwelcome comments he made to female peers about their feet. Novel use of exposure therapy helped him effectively decrease his comments from 1 to 2 times per month to once every 6 months.…

  13. Effects of lower limb amputation on the mental rotation of feet

    NARCIS (Netherlands)

    Curtze, Carolin; Otten, Bert; Postema, Klaas

    2010-01-01

    What happens to the mental representation of our body when the actual anatomy of our body changes? We asked 18 able-bodied controls, 18 patients with a lower limb amputation and a patient with rotationplasty to perform a laterality judgment task. They were shown illustrations of feet in different or

  14. Dragons with Clay Feet? : Transition, sustainable land use and rural environment in China and Vietnam

    NARCIS (Netherlands)

    Spoor, M.; Heerink, N.; Qu, F.

    2007-01-01

    Dragons with Clay Feet? presents state-of-the-art research on the impact of ongoing and anticipated economic policy and institutional reforms on agricultural development and sustainable rural resource in two East-Asian transition (and developing) economies--China and Vietnam.

  15. Towards surface analysis on diabetic feet soles to predict ulcerations using photometric stereo

    NARCIS (Netherlands)

    Liu, Chanjuan; Heijden, van der Ferdi; Netten, van Jaap J.; Vo-Dinh, Tuan; Mahadevan-Jansen, Anita; Grundfest, Warren

    2012-01-01

    Diabetic foot ulceration is a major complication for patients with diabetes mellitus. Approximately 15% to 25% of patients with Type I and Type II diabetes eventually develop feet ulcers. If not adequately treated, these ulcers may lead to foot infection, and ultimately to total (or partial) lower e

  16. Gross Square Feet Per Student. IssueTrak: A CEFPI Brief on Educational Facility Issues.

    Science.gov (United States)

    Wohlers, Art

    The Council of Educational Facility Planners International regularly provides the recommended number of gross square feet (gsf) per student figures. This report provides revised numbers based on responses from its Design Portfolio winners over the past 5 years. Average national averages of square footage space per student for Canada and the…

  17. Evaluating joint destruction in rheumatoid arthritis : is it necessary to radiograph both hands and feet?

    NARCIS (Netherlands)

    Knevel, R.; Kwok, K. Y.; de Rooy, D. P. C.; Posthumus, M. D.; Huizinga, T. W. J.; Brouwer, E.; van der Helm-van Mil, A. H. M.

    2013-01-01

    Background Radiological damage is an important outcome measure in rheumatoid arthritis (RA), both for research and clinical purposes. Depending on the setting, both hands and feet are radiographed, or only a part of these. It is unknown whether radiographing part of the four extremities gives compar

  18. Dragons with clay feet? Transition, sustainable land use, and rural environment in China and Vietnam

    NARCIS (Netherlands)

    Spoor, M.; Heerink, N.; Qu, F.

    2010-01-01

    Dragons with Clay Feet? presents state-of-the-art research on the impact of ongoing and anticipated economic policy and institutional reforms on agricultural development and sustainable rural resource in two East-Asian transition (and developing) economies--China and Vietnam. The contributions to th

  19. Foot placement modification for a biped humanoid robot with narrow feet.

    Science.gov (United States)

    Hashimoto, Kenji; Hattori, Kentaro; Otani, Takuya; Lim, Hun-Ok; Takanishi, Atsuo

    2014-01-01

    This paper describes a walking stabilization control for a biped humanoid robot with narrow feet. Most humanoid robots have larger feet than human beings to maintain their stability during walking. If robot's feet are as narrow as humans, it is difficult to realize a stable walk by using conventional stabilization controls. The proposed control modifies a foot placement according to the robot's attitude angle. If a robot tends to fall down, a foot angle is modified about the roll axis so that a swing foot contacts the ground horizontally. And a foot-landing point is also changed laterally to inhibit the robot from falling to the outside. To reduce a foot-landing impact, a virtual compliance control is applied to the vertical axis and the roll and pitch axes of the foot. Verification of the proposed method is conducted through experiments with a biped humanoid robot WABIAN-2R. WABIAN-2R realized a knee-bended walking with 30 mm breadth feet. Moreover, WABIAN-2R mounted on a human-like foot mechanism mimicking a human's foot arch structure realized a stable walking with the knee-stretched, heel-contact, and toe-off motion.

  20. Dynamic Characteristics of Prosthetic Feet: A Comparison Between Modal Parameters of Walking, Running and Sprinting Foot

    Science.gov (United States)

    Noroozi, S.; Rahman, A. G. A.; Dupac, M.; Vinney, J. E.

    Current methods of evaluating the performance of Energy Storing and Returning (ESR) prosthesis are subjective and rely on VO2 consumption. Current prosthetic feet are designed for specific applications and the majority are designed for walking and moderate running. These mechanical feet have fixed mechanical and dynamic characteristics. They have to be selected to meet the requirement of the task and any use outside the domain of the task can result in extreme/severe lack of gait symmetry and loss of energy. Poor gait symmetry results is excess consumption of energy, back pain or fatigue. To investigate if a multipurpose foot can be designed to passively adapt to the walking or running condition one must first understand the different dynamics that are involved and are required from the task specific foot. Static tests have shown these feet to have non-linear stiffness, making the prediction of their dynamic response difficult. The most reliable method to test for dynamic characteristics is drop and modal testing. A method approach has been developed as part of this research to test and compare the dynamic characteristics of three different types of foot (natural frequency, mode shapes and damping). This is needed to explore the differences in the responses of these feet that allow one to be used for walking, one to be used for running and one to be used for sprinting with ease.

  1. Is Epenthesis a Means to Optimize Feet? A Reanalysis of the CLPF Database

    Science.gov (United States)

    Taelman, Helena; Gillis, Steven

    2008-01-01

    Fikkert (1994) analyzed a large corpus of Dutch children's early language production, and found that they often add targetless syllables to their words in order to create bisyllabic feet. In this note we point out a methodological problem with that analysis: in an important number of cases, epenthetic vowels occur at places where grammatical…

  2. NASA/JPL Solar System Educators Program: Twelve Years of Success and Looking Forward

    Science.gov (United States)

    Ferrari, K.; NASA/JPL Solar System Educators Program

    2011-12-01

    Since 1999, the NASA/JPL Solar System Educators Program (SSEP) has been the model of a successful master teacher volunteer program. Integrating nationwide volunteers in this professional development program helped optimize agency funding set aside for education. Through the efforts of these volunteers, teachers across the country became familiarized with NASA's STEM (Science, Technology, Engineering and Mathematics) educational materials, schools added these products to their curriculum and students benefitted. The years since 1999 have brought about many changes. There have been advancements in technology that allow more opportunities for telecon and web based learning methods. Along with those advancements have also come significant challenges. With NASA budgets for education shrinking, this already frugal program has become more spartan. Teachers face their own hardships with school budget cuts, limited classroom time and little support for professional development. In order for SSEP to remain viable in the face of these challenges, the program management, mission funders and volunteers themselves are working together to find ways of maintaining the quality that made the program a success and at the same time incorporate new, cost-effective methods of delivery. The group will also seek new partnerships to provide enhancements that will aid educators in advancing their careers at the same time as they receive professional development. By working together and utilizing the talent and experience of these master teachers, the Solar System Educators Program can enjoy a revitalization that will meet the needs of today's educators at the same time as renewing the enthusiasm of the volunteers.

  3. Proceedings of the 2003 NASA/JPL Workshop on Fundamental Physics in Space

    Science.gov (United States)

    Strayer, Don (Editor)

    2003-01-01

    The 2003 Fundamental Physics workshop included presentations ranging from forces acting on RNA to properties of clouds of degenerate Fermi atoms, to techniques to probe for a added space-time dimensions, and to flight hardware for low temperature experiments, amongst others. Mark Lee from NASA Headquarters described the new strategic plan that NASA has developed under Administrator Sean O'Keefe's leadership. Mark explained that the Fundamental Physics community now needs to align its research program and the roadmap describing the long-term goals of the program with the NASA plan. Ulf Israelsson of JPL discussed how the rewrite of the roadmap will be implemented under the leadership of the Fundamental Physics Discipline Working Group (DWG). Nick Bigelow, chair of the DWG, outlined how investigators can contribute to the writing of the roadmap. Results of measurements on very cold clouds of Fermi atoms near a Feshbach resonance were described by three investigators. Also, new measurements relating to tests of Einstein equivalence were discussed. Investigators also described methods to test other aspects of Einstein's relativity theories.

  4. IDS evaluation of the DORIS versions of the DGFI, IGN and JPL ITRF2014 solutions

    Science.gov (United States)

    Moreaux, Guilhem; Capdeville, Hugues; Lemoine, Jean-Michel; Ferrage, Pascale

    2016-04-01

    In the context of the 2014 realization of the International Terrestrial Reference Frame, the three IERS Production Centers (DGFI, IGN and JPL) delivered three independent solutions from the contributions of the four space geodetic techniques (DORIS, GNSS, SLR and VLBI). Even if these three ITRF2014 realizations are based on the same input, they differ on several points such as the space geodetic techniques weighting, the estimation of station velocities or the modelization of post-seismic deformation. The primary objective of this study is to analyze the DORIS part of these three realizations of ITRF2014 in terms of (1) position and velocity discontinuities; (2) geocenter and scale; (3) stations position residuals; (4) DORIS tie-vectors. This analyze will be based on the solution files of the IDS contribution to ITRF2014 as well as on its extension to 2015. Furthermore, we will estimate the impact of these three ITRF2014 solutions on DORIS orbit determination. Then, we will address recommendations to the DORIS community of the use of these three ITRF2014 solutions.

  5. NASA/JPL CLIMATE DAY: Middle and High School Students Get the Facts about Global Climate Change

    Science.gov (United States)

    Richardson, Annie; Callery, Susan; Srinivasan, Margaret

    2013-04-01

    In 2007, NASA Headquarters requested that Earth Science outreach teams brainstorm new education and public outreach activities that would focus on the topic of global climate change. At the Jet Propulsion Laboratory (JPL), Annie Richardson, outreach lead for the Ocean Surface Topography missions came up with the idea of a "Climate Day", capitalizing on the popular Earth Day name and events held annually throughout the world. JPL Climate Day would be an education and public outreach event whose objectives are to provide the latest scientific facts about global climate change - including the role the ocean plays in it, the contributions that NASA/JPL satellites and scientists make to the body of knowledge on the topic, and what we as individuals can do to promote global sustainability. The primary goal is that participants get this information in a fun and exciting environment, and walk away feeling empowered and capable of confidently engaging in the global climate debate. In March 2008, JPL and its partners held the first Climate Day event. 950 students from seven school districts heard from five scientists; visited exhibits, and participated in hands-on-activities. Pleased with the outcome, we organized JPL Climate Day 2010 at the Pasadena Convention Center in Pasadena, California, reaching more than 1700 students, teachers, and members of the general public over two days. Taking note of this successful model, NASA funded a multi-center, NASA Climate Day proposal in 2010 to expand Climate Day nation-wide. The NASA Climate Day proposal is a three-pronged project consisting of a cadre of Earth Ambassadors selected from among NASA-affiliated informal educators; a "Climate Day Kit" consisting of climate-related electronic resources available to the Earth Ambassadors; and NASA Climate Day events to be held in Earth Ambassador communities across the United States. NASA/JPL continues to host the original Climate Day event and in 2012 held its 4th event, at the Pasadena

  6. Phase diagrams and synthesis of cubic boron nitride

    CERN Document Server

    Turkevich, V Z

    2002-01-01

    On the basis of phase equilibria, the lowest temperatures, T sub m sub i sub n , above which at high pressures cubic boron nitride crystallization from melt solution is allowable in terms of thermodynamics have been found for a number of systems that include boron nitride.

  7. Interaction of dispersed cubic phases with blood components

    DEFF Research Database (Denmark)

    Bode, J C; Kuntsche, Judith; Funari, S S;

    2013-01-01

    The interaction of aqueous nanoparticle dispersions, e.g. based on monoolein/poloxamer 407, with blood components is an important topic concerning especially the parenteral way of administration. Therefore, the influence of human and porcine plasma on dispersed cubic phases was investigated...

  8. Cubic surfaces and their invariants: Some memories of Raymond Stora

    Science.gov (United States)

    Bauer, Michel

    2016-11-01

    Cubic surfaces embedded in complex projective 3-space are a classical illustration of the use of old and new methods in algebraic geometry. Recently, they made their appearance in physics, and in particular aroused the interest of Raymond Stora, to the memory of whom these notes are dedicated, and to whom I'm very much indebted. Each smooth cubic surface has a rich geometric structure, which I review briefly, with emphasis on the 27 lines and the combinatorics of their intersections. Only elementary methods are used, relying on first order perturbation/deformation theory. I then turn to the study of the family of cubic surfaces. They depend on 20 parameters, and the action of the 15 parameter group SL4 (C) splits the family in orbits depending on 5 parameters. This takes us into the realm of (geometric) invariant theory. I review briefly the classical theorems on the structure of the ring of polynomial invariants and illustrate its many facets by looking at a simple example, before turning to the already involved case of cubic surfaces. The invariant ring was described in the 19th century. I show how to retrieve this description via counting/generating functions and character formulae.

  9. Exact solutions for the cubic-quintic nonlinear Schroedinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Jiamin [Department of Physics, Zhejiang Lishui University, Lishui 323000 (China)]. E-mail: zjm64@163.com; Ma Zhengyi [Department of Physics, Zhejiang Lishui University, Lishui 323000 (China); Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072 (China)

    2007-08-15

    In this paper, the cubic-quintic nonlinear Schroedinger equation is solved through the extended elliptic sub-equation method. As a consequence, many types of exact travelling wave solutions are obtained which including bell and kink profile solitary wave solutions, triangular periodic wave solutions and singular solutions.

  10. Combinatorics on Words in Symbolic Dynamics: the Antisymmetric Cubic Map

    Institute of Scientific and Technical Information of China (English)

    Wan Ji DAI; Kebo L(U); Jun WANG

    2008-01-01

    This paper is contributed to the combinatorial properties of the periodic kneading words of antisymmetric cubic maps defined on a interval.The least words of given lengths,the adjacency relations on the words of given lengths and the parity-alternative property in some sets of such words are established.

  11. A Unified Approach to Teaching Quadratic and Cubic Equations.

    Science.gov (United States)

    Ward, A. J. B.

    2003-01-01

    Presents a simple method for teaching the algebraic solution of cubic equations via completion of the cube. Shows that this method is readily accepted by students already familiar with completion of the square as a method for quadratic equations. (Author/KHR)

  12. Orientational phase transition in cubic liquid crystals with positional order

    OpenAIRE

    Pokrovsky, V.L.; Saidachmetov, P.A.

    1988-01-01

    An electric field can give rise to a shear deformation of a cubic liquid crystal with long-range positional order fixed by two plates. The critical value of the field does not depend on the size of the system and depends crucially on the orientation.

  13. An effective packing density of binary cubic crystals

    Science.gov (United States)

    Eremin, I. E.; Eremina, V. V.; Sychev, M. S.; Moiseenko, V. G.

    2015-04-01

    The methodology of effective macroscopic calculation of numerical values of internuclear distances in binary crystals of a cubic crystal system is based on the use of coefficients of the structural packing density of the crystal lattice. The possibility of combining the reference data on the main physicochemical parameters of the substance is implemented by synthesis of the corresponding mathematical models.

  14. Trapping of cubic ZnO nanocrystallites at ambient conditions

    DEFF Research Database (Denmark)

    Decremps, F.; Pellicer-Porres, J.; Datchi, F.

    2002-01-01

    Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cubic structure after a heat treatment at high pressure (15 GPa and 550 K). Combined x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) experiments have been performed to probe both long-ra...

  15. Specific heat of the simple-cubic Ising model

    NARCIS (Netherlands)

    Feng, X.; Blöte, H.W.J.

    2010-01-01

    We provide an expression quantitatively describing the specific heat of the Ising model on the simple-cubic lattice in the critical region. This expression is based on finite-size scaling of numerical results obtained by means of a Monte Carlo method. It agrees satisfactorily with series expansions

  16. Connecting the Dots Parametrically: An Alternative to Cubic Splines.

    Science.gov (United States)

    Hildebrand, Wilbur J.

    1990-01-01

    Discusses a method of cubic splines to determine a curve through a series of points and a second method for obtaining parametric equations for a smooth curve that passes through a sequence of points. Procedures for determining the curves and results of each of the methods are compared. (YP)

  17. Cubic spline approximation techniques for parameter estimation in distributed systems

    Science.gov (United States)

    Banks, H. T.; Crowley, J. M.; Kunisch, K.

    1983-01-01

    Approximation schemes employing cubic splines in the context of a linear semigroup framework are developed for both parabolic and hyperbolic second-order partial differential equation parameter estimation problems. Convergence results are established for problems with linear and nonlinear systems, and a summary of numerical experiments with the techniques proposed is given.

  18. Rheology of cubic particles suspended in a Newtonian fluid.

    Science.gov (United States)

    Cwalina, Colin D; Harrison, Kelsey J; Wagner, Norman J

    2016-05-18

    Many real-world industrial processes involve non-spherical particles suspended in a fluid medium. Knowledge of the flow behavior of these suspensions is essential for optimizing their transport properties and designing processing equipment. In the present work, we explore and report on the rheology of concentrated suspensions of cubic-shaped colloidal particles under steady and dynamic shear flow. These suspensions exhibit a rich non-Newtonian rheology that includes shear thickening and normal stress differences at high shear stresses. Scalings are proposed to connect the material properties of these suspensions of cubic particle to those measured for suspensions of spherical particles. Negative first normal stress differences indicate that lubrication hydrodynamic forces dominate the stress in the shear-thickened state. Accounting for the increased lubrication hydrodynamic interactions between the flat surfaces of the cubic particles allows for a quantitative comparison of the deviatoric stress in the shear-thickened state to that of spherical particles. New semi-empirical models for the viscosity and normal stress difference coefficients are presented for the shear-thickened state. The results of this study indicate that cubic particles offer new and unique opportunities to formulate colloidal dispersions for field-responsive materials.

  19. Infinite Face Centered Cubic Network of Identical Resistors

    CERN Document Server

    Asad, J H

    2012-01-01

    The equivalent resistance between the origin and any other lattice site, in an infinite Face Centered Cubic network consisting from identical resistors, has been expressed rationally in terms of the known value and . The asymptotic behavior is investigated, and some calculated values for the equivalent resistance are presented.

  20. Trace spaces in a pre-cubical complex

    DEFF Research Database (Denmark)

    Raussen, Martin

    In directed algebraic topology, (spaces of) directed irreversible (d)-paths are studied from a topological and from a categorical point of view. Motivated by models for concurrent computation, we study in this paper spaces of d-paths in a pre-cubical complex. Such paths are equipped with a natural...

  1. Morphosynthesis of cubic silver cages on monolithic activated carbon.

    Science.gov (United States)

    Wang, Fei; Zhao, Hong; Lai, Yijian; Liu, Siyu; Zhao, Binyuan; Ning, Yuesheng; Hu, Xiaobin

    2013-11-14

    Cubic silver cages were prepared on monolithic activated carbon (MAC) pre-absorbed with Cl(-), SO4(2-), or PO4(3-) anions. Silver insoluble salts served as templates for the morphosynthesis of silver cages. The silver ions were reduced by reductive functional groups on MAC micropores through a galvanic cell reaction mechanism.

  2. SUPERCONVERGENCE ANALYSIS FOR CUBIC TRIANGULAR ELEMENT OF THE FINITE ELEMENT

    Institute of Scientific and Technical Information of China (English)

    Qi-ding Zhu

    2000-01-01

    In this paper, we construct a projection interpolation for cubic triangular ele- ment by using othogonal expansion triangular method. We show two fundamental formulas of estimation on a special partion and obtain a superconvergence result of 1 -e order higher for the placement function and its tangential derivative on the third order Lobatto points and Gauss points on each edge of triangular element.

  3. Integrability of Lotka-Volterra Planar Complex Cubic Systems

    Science.gov (United States)

    Dukarić, Maša; Giné, Jaume

    In this paper, we study the Lotka-Volterra complex cubic systems. We obtain necessary conditions of integrability for these systems with some restriction on the parameters. The sufficiency is proved for all conditions, except one which remains open, using different methods.

  4. Global Well-Posedness for Cubic NLS with Nonlinear Damping

    KAUST Repository

    Antonelli, Paolo

    2010-11-04

    We study the Cauchy problem for the cubic nonlinear Schrödinger equation, perturbed by (higher order) dissipative nonlinearities. We prove global in-time existence of solutions for general initial data in the energy space. In particular we treat the energy-critical case of a quintic dissipation in three space dimensions. © Taylor & Francis Group, LLC.

  5. A STUDY ON PREVALENCE OF FLAT FEET AMONG SCHOOL CHILDREN IN KANCHIPURAM POPULATION

    Directory of Open Access Journals (Sweden)

    D.Krupa Daniel

    2015-09-01

    Full Text Available Background: A flexible flatfoot is considered to be a variation of a normal foot. Any deviation from the anatomical plantigrade foot is a deformed foot. Some of the deformities of the foot are: Flat Foot. The normal concavity due to the medial longitudinal arch is absent. High Arch Foot - A normal foot has a medial longitudinal arch which is higher. Materials and Methods: A total population of 625, in age ranging from 5 year to 9 years in Kanchipuram district was chosen. Each individual was made to sit and the foot was brought in contact with the Foot Impression gaining Kit on white sheets in standing posture. Results: The flat feet and high arch feet evaluation was obtained by means of foot prints and the plantar arch index was established. The mean values of plantar arch index within the age group were stable and ranges from 0.72 to 0.73. With plantar arch indices greater than 1.15 was regarded as flatfeet and less than 0.10 was regarded as High arch feet. Discussion: In normal feet with presence of an arch, the stress will be distributed in an even manner so that the person will not experience any kind of pain. Under an abnormal condition that occurs due to lack of stretching of muscles, bones and tendons, there will be absence of arch among these people. In this condition, all the weight will be concentrated in smaller area on the feet and generates a lot more pain than normal. This condition might occur in both children and adults. In some people both feet will be flat and in some only one foot will be flat. Conclusion: Flat foot is highly prevalent in the ages between 5-9. The average values for plantar arch indices are stable and ranges from 0.72 to 0.73 in our sample regarded as Normal foot. Plantar arch index > 1.15 is regarded as Flat foot. Plantar arch index < 0.10 is regarded as High arch foot.

  6. NASA JPL Distributed Systems Technology (DST) Object-Oriented Component Approach for Software Inter-Operability and Reuse

    Science.gov (United States)

    Hall, Laverne; Hung, Chaw-Kwei; Lin, Imin

    2000-01-01

    The purpose of this paper is to provide a description of NASA JPL Distributed Systems Technology (DST) Section's object-oriented component approach to open inter-operable systems software development and software reuse. It will address what is meant by the terminology object component software, give an overview of the component-based development approach and how it relates to infrastructure support of software architectures and promotes reuse, enumerate on the benefits of this approach, and give examples of application prototypes demonstrating its usage and advantages. Utilization of the object-oriented component technology approach for system development and software reuse will apply to several areas within JPL, and possibly across other NASA Centers.

  7. (Nearly) Fifteen Years of Altimetry Outreach at CNES and NASA/JPL

    Science.gov (United States)

    Rosmorduc, V.; Richardson, A.; Srinivasan, M.

    2006-07-01

    Since the 1992 launch of Topex/Poseidon, CNES and NASA/JPL have been involved in providing information about satellite altimetry techniques, applications, and ocean science to the world. From the beginning, the TOPEX/Poseidon and Jason-1 Outreach Team has focused on reaching out to a wide range of people: from educators, students and the general public, to scientists and professionals who use the data. Our objective is to provide information and support appropriate to each audience. We have developed an extensive series of products on many relevant topics related to ocean science and altimetry, with levels ranging from easy-to-read to the expert point of view. Through presentation of mission first results, the focus in the early years was on data quality and the varied data applications. Since 1997, El Niño forecasting was of major interest to the public, whereas the oceanographic community sought contributions to true operational oceanography. With the launch of Jason-1, the focus is now on the need for a long-term data series and continuity in the missions. Educational activities related to ocean altimetry are continuing and expanding. Our aim in this realm is to help teachers and students across the world appreciate the ocean environment and the role satellites play in increasing our understanding of this crucial resource. The evolution in our outreach activities is mirrored in the printed material distributed as hardcopy, and significantly in the regular updates to the web sites. As we approach nearly 15 years of continuous altimetry outreach our efforts are directed toward supporting the move toward operational oceanography (with GODAE and Jason-2/OSTM) and converging upon an integrated, multi-institutional outreach program.

  8. Exploring Mission Concepts with the JPL Innovation Foundry A-Team

    Science.gov (United States)

    Ziemer, John K.; Ervin, Joan; Lang, Jared

    2013-01-01

    The JPL Innovation Foundry has established a new approach for exploring, developing, and evaluating early concepts called the A-Team. The A-Team combines innovative collaborative methods with subject matter expertise and analysis tools to help mature mission concepts. Science, implementation, and programmatic elements are all considered during an A-Team study. Methods are grouped by Concept Maturity Level (CML), from 1 through 3, including idea generation and capture (CML 1), initial feasibility assessment (CML 2), and trade space exploration (CML 3). Methods used for each CML are presented, and the key team roles are described from two points of view: innovative methods and technical expertise. A-Team roles for providing innovative methods include the facilitator, study lead, and assistant study lead. A-Team roles for providing technical expertise include the architect, lead systems engineer, and integration engineer. In addition to these key roles, each A-Team study is uniquely staffed to match the study topic and scope including subject matter experts, scientists, technologists, flight and instrument systems engineers, and program managers as needed. Advanced analysis and collaborative engineering tools (e.g. cost, science traceability, mission design, knowledge capture, study and analysis support infrastructure) are also under development for use in A-Team studies and will be discussed briefly. The A-Team facilities provide a constructive environment for innovative ideas from all aspects of mission formulation to eliminate isolated studies and come together early in the development cycle when they can provide the biggest impact. This paper provides an overview of the A-Team, its study processes, roles, methods, tools and facilities.

  9. Modeling solar cell degradation in space: a comparison of the NRL displacement damage dose and the JPL equivalent fluence approaches

    Energy Technology Data Exchange (ETDEWEB)

    Messenger, S.R. [SFA Inc., Largo, MD (United States); Summers, G.P. [US Naval Research Laboratory, Washington, DC (United States); University of Maryland, Baltimore, MD (United States); Walters, R.J.; Xapsos, M.A. [US Naval Research Laboratory, Washington, DC (United States); Burke, E.A.

    2001-07-01

    The method for predicting solar cell degradation in space radiation environments developed recently at the US Naval Research Laboratory (NRL) is compared in detail with the earlier method developed at the US Jet Propulsion Laboratory (JPL). Although both methods are similar, the key difference is that in the NRL approach, the energy dependence of the damage coefficients is determined from a calculation of the nonionizing energy loss (NIEL) and requires relatively few experimental measurements, whereas in the JPL method the damage coefficients have to be determined using an extensive set of experimental measurements. The end result of the NRL approach is a determination of a single characteristic degradation curve for a cell technology, which is measured against displacement damage dose rather than fluence. The end-of-life (EOL) cell performance for a particular mission can be read from the characteristic curve once the displacement damage dose for the mission has been determined. In the JPL method, the end result is a determination of the equivalent 1 MeV electron fluence, which would cause the same level of degradation as the actual space environment. The two approaches give similar results for GaAs/Ge solar cells, for which a large database exists. Because the NRL method requires far less experimental data than the JPL method, it is more readily applied to emerging cell technologies for which extensive radiation measurements are not available. The NRL approach is being incorporated into a code named SAVANT by researchers at NASA Glenn Research Center. The predictions of SAVANT are shown to agree closely with actual space data for GaAs/Ge and CuInSe{sub 2} cells flown on the Equator-S mission. (author)

  10. Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

    Science.gov (United States)

    Huang, Yan; Wang, Qi-Ning; Gao, Yue; Xie, Guang-Ming

    2012-10-01

    Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait. This paper presents a passive dynamic walking model with segmented feet, which makes the bipedal walking gait more close to natural human-like gait. The proposed model extends the simplest walking model with the addition of flat feet and torsional spring based compliance on ankle joints and toe joints, to achieve stable walking on a slope driven by gravity. The push-off phase includes foot rotations around the toe joint and around the toe tip, which shows a great resemblance to human normal walking. This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

  11. Foot Placement Indicator for Balance of Planar Bipeds with Point Feet

    Directory of Open Access Journals (Sweden)

    Pieter van Zutven

    2013-05-01

    Full Text Available Abstract If humanoid robots are to be used in society, they should be able to maintain their balance. Knowing where to step is crucially important. In this paper we contribute an algorithm that can compute the foot step location such that bipedal balance is maintained for planar bipeds with point feet and an arbitrary number of non-massless links on a horizontal and flat ground. The algorithm is called the foot placement indicator (FPI and it extends the foot placement estimator (FPE. The FPE uses an inverted pendulum model to capture the dynamics of a humanoid robot, whereas the FPI deals with multi-body models with distributed masses. This paper analyses equilibrium sets and the stability of planar bipeds with point feet. The algorithm uses conservation of energy throughout the step, taking into account the instantaneous impact dynamics at foot strike. A simulation case study on a five-link planar biped shows the effectiveness of the FPI.

  12. Gait analysis and energy consumption of below-knee amputees wearing three different prosthetic feet.

    Science.gov (United States)

    Huang, G F; Chou, Y L; Su, F C

    2000-10-01

    This study scientifically measures the dynamic gait characteristics and energy consumption of 16 male below-knee amputees, eight vascular and eight traumatic, while wearing solid ankle cushion heel (SACH), single axis and multiple axis prosthetic feet via six-camera motion analysis, metabolic measurement cart and heavy-duty treadmill. Subjective results are additionally determined via questionnaire after testing. Motion analysis showed statistically significant differences at Pmultiple axis foot in the velocity, cadence, stride length and single limb stance. Significant differences were found in energy consumption between the traumatic and vascular groups, and significant changes in walking under different speeds and different inclines. Results provide quantitative and qualitative information about the dynamic performance of the various feet, which can be helpful in prescribing the optimal prosthetic foot for individual amputees.

  13. Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

    Institute of Scientific and Technical Information of China (English)

    Yan Huang; Qi-Ning Wang; Yue Gao; Guang-Ming Xie

    2012-01-01

    Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait.This paper presents a passive dynamic walking model with segmented feet,which makes the bipedal walking gait more close to natural human-like gait.The proposed model extends the simplest walking model with the addition of flat feet and torsional spring based compliance on ankle joints and toe joints,to achieve stable walking on a slope driven by gravity.The push-off phase includes foot rotations around the toe joint and around the toe tip,which shows a great resemblance to human normal walking.This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

  14. Biped 4R2C six-bar mechanism with inner and outer feet

    Science.gov (United States)

    Liu, Chao; Wang, Hao; Yao, Yan-an

    2016-01-01

    Most current biped robots are equipped with two feet arranged in the right and left which inspired by the human body system. Different from the existing configurations, a novel biped robot with inner and outer feet based on a spatial six-bar 4R2C(R and C denote revolute and cylindric joints, respectively) mechanism is proposed. It can move along a line or a curve by three walking modes that are dwell adjustment mode, limit position adjustment mode and any position adjustment mode. Kinematic, gait planning and stability analyses are performed respectively, and a prototype is developed. Lastly, a potential application is considered and two manipulating modes(sphere and cylinder manipulating modes) are carried out. This interesting mechanism feathering its single closed-chain structure and unique work performance is expected to motivate the configuration creation of biped robots.

  15. Genu Valgum and Flat Feet in Children With Healthy and Excessive Body Weight.

    Science.gov (United States)

    Jankowicz-Szymanska, Agnieszka; Mikolajczyk, Edyta

    2016-01-01

    To examine the relationship between obesity, genu valgum, and flat feet in children, and find practical implications for therapeutic interventions. A total of 1364 children aged 3-7 years took part in the research. Their body mass index was calculated and their weight status described. Participants' knee alignment was assessed by measuring the intermalleolar distance in the standing position with the knees in contact. The height of the longitudinal arch of each foot was measured using Clarke's angle. The prevalence of overweight and obesity increased with age. Reduction of intermalleolar distance and increased longitudinal arch of the foot, characteristic of typical growth and development, were observed. Genu valgum was more common in children who were overweight. Significant correlations among body mass index, intermalleolar distance, and Clarke's angle (P genu valgum and flat feet.

  16. Foot Placement Indicator for Balance of Planar Bipeds with Point Feet

    Directory of Open Access Journals (Sweden)

    Pieter van Zutven

    2013-05-01

    Full Text Available If humanoid robots are to be used in society, they should be able to maintain their balance. Knowing where to step is crucially important. In this paper we contribute an algorithm that can compute the foot step location such that bipedal balance is maintained for planar bipeds with point feet and an arbitrary number of non‐massless links on a horizontal and flat ground. The algorithm is called the foot placement indicator (FPI and it extends the foot placement estimator (FPE. The FPE uses an inverted pendulum model to capture the dynamics of a humanoid robot, whereas the FPI deals with multi‐body models with distributed masses. This paper analyses equilibrium sets and the stability of planar bipeds with point feet. The algorithm uses conservation of energy throughout the step, taking into account the instantaneous impact dynamics at foot strike. A simulation case study on a five‐link planar biped shows the effectiveness of the FPI.

  17. Stability and control of dynamic walking for a five-link planar biped robot with feet

    Institute of Scientific and Technical Information of China (English)

    Chenglong FU; Ken CHEN; Jing XIONG; Leon XU

    2007-01-01

    During dynamic walking of biped robots, the underactuated rotating degree of freedom (DOF) emerges between the support foot and the ground, which makes the biped model hybrid and dimension-variant. This paper addresses the asymptotic orbit stability for dimension-variant hybrid systems (DVHS). Based on the generalized Poincare map, the stability criterion for DVHS is also presented, and the result is then used to study dynamic walking for a five-link planar biped robot with feet. Time-invariant gait planning and nonlinear control strategy for dynamic walking with flat feet is also introduced. Simulation results indicate that an asymptotically stable limit cycle of dynamic walking is achieved by the proposed method.

  18. Dynamics and Optimal Feet Force Distributions of a Realistic Four-legged Robot

    Directory of Open Access Journals (Sweden)

    Saurav Agarwal

    2012-08-01

    Full Text Available This paper presents a detailed dynamic modeling of realistic four-legged robot. The direct and inverse kinematic analysis for each leg has been considered in order to develop an overall kinematic model of the robot, when it follows a straight path. This study also aims to estimate optimal feet force distributions of the said robot, which is necessary for its real-time control. Three different approaches namely, minimization of norm of feet forces (approach 1, minimization of norm of joint torques (approach 2 and minimization of norm of joint power (approach 3 have been developed. Simulation result shows that approach 3 is more energy efficient foot force formulation than other two approaches. Lagrange-Euler formulation has been utilized to determine the joint torques. The developed dynamic models have been examined through computer simulation of continuous gait of the four-legged robot.

  19. Testing the validity of the Danish urban myth that alcohol can be absorbed through feet: open labelled self experimental study

    DEFF Research Database (Denmark)

    Hansen, Christian Stevns; Færch, Louise; Kristensen, Peter Lommer

    2010-01-01

    To determine the validity of the Danish urban myth that it is possible to get drunk by submerging feet in alcohol.......To determine the validity of the Danish urban myth that it is possible to get drunk by submerging feet in alcohol....

  20. Postural stability effects of random vibration at the feet of construction workers in simulated elevation.

    Science.gov (United States)

    Simeonov, P; Hsiao, H; Powers, J; Ammons, D; Kau, T; Amendola, A

    2011-07-01

    The risk of falls from height on a construction site increases under conditions which degrade workers' postural control. At elevation, workers depend heavily on sensory information from their feet to maintain balance. The study tested two hypotheses: "sensory enhancement"--sub-sensory (undetectable) random mechanical vibrations at the plantar surface of the feet can improve worker's balance at elevation; and "sensory suppression"--supra-sensory (detectable) random mechanical vibrations can have a degrading effect on balance in the same experimental settings. Six young (age 20-35) and six aging (age 45-60) construction workers were tested while standing in standard and semi-tandem postures on instrumented gel insoles. The insoles applied sub- or supra-sensory levels of random mechanical vibrations to the feet. The tests were conducted in a surround-screen virtual reality system, which simulated a narrow plank at elevation on a construction site. Upper body kinematics was assessed with a motion-measurement system. Postural stability effects were evaluated by conventional and statistical mechanics sway measures, as well as trunk angular displacement parameters. Analysis of variance did not confirm the "sensory enhancement" hypothesis, but provided evidence for the "sensory suppression" hypothesis. The supra-sensory vibration had a destabilizing effect, which was considerably stronger in the semi-tandem posture and affected most of the sway variables. Sensory suppression associated with elevated vibration levels on a construction site may increase the danger of losing balance. Construction workers at elevation, e.g., on a beam or narrow plank might be at increased risk of fall if they can detect vibrations under their feet. To reduce the possibility of losing balance, mechanical vibration to supporting structures used as walking/working surfaces should be minimized when performing construction tasks at elevation. Published by Elsevier Ltd.

  1. SOCIAL SPACE, LANGUAGE, AND CONSCIOUSNESS IN HELENA MARÍA VIRAMONTES'S UNDER THE FEET OF JESUS

    Directory of Open Access Journals (Sweden)

    Michael Nieto Garcia

    2004-02-01

    Full Text Available This paper analyzes social space with the tool of postmodern theories of space in the specific case of migrant agricultural workers portrayed in Helena María Viramontes's Under the Feet of Jesus. Language and consciousness are the main vehicles by which Estrella, the central protagonist of the novel, liberates herself from the dominant social discourses-linguistic, racial, economic, and gender-that position her as a neocolonial subject.

  2. Six Feet Under o la muerte nuestra de cada día

    Directory of Open Access Journals (Sweden)

    Francisco Guillermo Medina Montaño

    2015-12-01

    Full Text Available A partir del modelo de análisis ADN de las series televisivas, los autores abordan la serie Six Feet Under, su estructura narrativa, su lenguaje audiovisual, así como la construcción psicológica y moral de los personajes que en ella convergen para así escudriñar los mensajes y valores de una de las obras más vistas en su tipo y en su tiempo.

  3. Variations in daily quality assurance dosimetry from device levelling, feet position and backscatter material.

    Science.gov (United States)

    Ceylan, Abdurrahman; Butson, Martin; Cullen, Ashley; Yu, Peter K N; Alnawaf, Hani

    2012-12-01

    Daily quality assurance procedures are an essential part of radiotherapy medical physics. Devices such as the Sun Nuclear, DQA3 are effective tools for analysis of daily dosimetry including flatness, symmetry, energy, field size and central axis radiation dose measurement. The DQA3 can be used on the treatment couch of the linear accelerator or on a dedicated table/bed for superficial and orthovoltage x-ray machines. This device is levelled using its dedicated feet. This work has shown that depending on the quantity of backscatter material behind the DQA3 device, the position of the levelling feet can affect the measured central axis dose by up to 1.8 % (250 kVp and 6 MV) and that the introduction of more backscatter material behind the DQA3 can lead to up to 7.2 % (6 MV) variations in measured central axis dose. In conditions where no backscatter material is present, dose measurements can vary up to 1 %. As such this work has highlighted the need to keep the material behind the DQA3 device constant as well as maintaining the accuracy of the feet position on the device to effectively measure the most accurate daily constancy achievable. Results have also shown that variations in symmetry and energy calculations of up to 1 % can occur if the device is not levelled appropriately. As such, we recommend the position of the levelling feet on the device be as close as possible to the device so that a constant distance is kept between the DQA3 and the treatment couch and thus minimal levelling variations also occur. We would also recommend having no extra backscattering material behind the DQA3 device during use to minimise any variations which might occur from these backscattering effects.

  4. Spinal cord lesions shrink peripersonal space around the feet, passive mobilization of paraplegic limbs restores it.

    Science.gov (United States)

    Scandola, Michele; Aglioti, Salvatore Maria; Bonente, Claudio; Avesani, Renato; Moro, Valentina

    2016-04-06

    Peripersonal space (PPS) is the space surrounding us within which we interact with objects. PPS may be modulated by actions (e.g. when using tools) or sense of ownership (e.g. over a rubber hand). Indeed, intense and/or prolonged use of a tool may induce a sense of ownership over it. Conversely, inducing ownership over a rubber hand may activate brain regions involved in motor control. However, the extent to which PPS is modulated by action-dependent or ownership-dependent mechanisms remains unclear. Here, we explored the PPS around the feet and the sense of ownership over lower limbs in people with Paraplegia following Complete spinal cord Lesions (PCL) and in healthy subjects. PCL people can move their upper body but have lost all sensory-motor functions in their lower body (e.g. lower limbs). We tested whether PPS alterations reflect the topographical representations of various body parts. We found that the PPS around the feet was impaired in PCL who however had a normal representation of the PPS around the hands. Significantly, passive mobilization of paraplegic limbs restored the PPS around the feet suggesting that activating action representations in PCL brings about short-term changes of PPS that may thus be more plastic than previously believed.

  5. Function of the triceps surae muscle group in low and high arched feet: an exploratory study.

    Science.gov (United States)

    Branthwaite, Helen; Pandyan, Anand; Chockalingam, Nachiappan

    2012-06-01

    The Achilles tendon has been shown to be comprised of segmental components of tendon arising from the tricpes surae muscle group. Motion of the foot joints in low and high arched feet may induce a change in behaviour of the triceps surae muscle group due to altered strain on the tendon. Surface electromyogram of the medial and lateral gastrocnemius and the soleus muscle from 12 subjects (with 6 low arched and 6 high arched feet) (1:1) was recorded whilst walking at a self selected speed along a 10m walkway. The results showed a high variability in muscle activity between groups with patterns emerging within groups. Soleus was more active in 50% of the low arch feet at forefoot loading and there was a crescendo of activity towards heel lift in 58% of all subjects. This observed variability between groups and foot types emphasises the need for further work on individual anatomical variation and foot function to help in the understanding and management of Achilles tendon pathologies and triceps surae dysfunction.

  6. Enhanced stress response by a bilateral feet compared to a unilateral hand Cold Pressor Test.

    Science.gov (United States)

    Larra, Mauro F; Schilling, Thomas M; Röhrig, Philipp; Schächinger, Hartmut

    2015-01-01

    The Cold Pressor Test (CPT) is a frequently employed laboratory stress protocol. However, with many experimental designs the application in its classic form (immersion of the dominant hand into ice-water) is problematic as unilateral stimulation may need to be avoided and/or hands are required for further measurements. Here, we describe a simple modification of the classic CPT in which both feet are immersed into ice-water and compare the evoked neuroendocrine stress response to the classic CPT in a within-subjects design. Twenty-four healthy participants were exposed to each of both CPT versions on two subsequent days in randomized order. Heart rate, blood pressure, salivary alpha-amylase and cortisol were measured at baseline and during or after CPT exposition, respectively, along with subjective ratings of pain and stress. The bilateral feet CPT induced marked increases in all measured stress parameters. Moreover, with the exception of blood pressure, autonomic and endocrine responses were enhanced compared to the classic CPT. The bilateral feet CPT thus is a valid and simple modification and may be useful when the application of the classic CPT is unfeasible or a stronger neuroendocrine stress response is of interest.

  7. Effect of medial arterial calcification on O2 supply to exercising diabetic feet.

    Science.gov (United States)

    Chantelau, E; Ma, X Y; Herrnberger, S; Dohmen, C; Trappe, P; Baba, T

    1990-08-01

    We investigated whether medial arterial calcification (MAC) impairs O2 supply to the exercising foot in diabetic patients with foot lesions. Transcutaneous O2 tension (tcPO2) was monitored at the dorsum of the foot before and after bicycle exercise in 11 diabetic patients with peripheral ischemic vascular disease (PIVD) with or without concomitant existence of MAC, 10 patients with MAC but without PIVD, 10 diabetic control subjects, and 6 nondiabetic control subjects. The mean preexercise tcPO2 level was comparable in these four groups. However, tcPO2 decreased significantly with exercise in feet with PIVD (mean +/- SE -17.9 +/- 2.7%, P less than 0.01, n = 11), regardless of presence or absence of vascular calcification. On the other hand, the value increased significantly with exercise in feet with MAC but without PIVD (21.2 +/- 3.5%, P less than 0.01, n = 10) and in those of diabetic control subjects (14.9 +/- 3.6%, P less than 0.01), respectively. The tcPO2 remained unchanged in the feet of nondiabetic control subjects (1.7 +/- 1.1%). The results suggest that MAC is not associated with reduced O2 supply to the exercising foot in diabetic patients.

  8. Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon [Hallym University College of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

  9. Evidence for rotational motions in the feet of a quiescent solar prominence

    CERN Document Server

    Suárez, D Orozco; Bueno, J Trujillo

    2012-01-01

    We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent hedgerow prominence. The data show opposite Doppler shifts, +/- 6 km/s, at the edges of the prominence feet. We argue that these shifts may be interpreted as prominence plasma rotating counterclockwise around the vertical axis to the solar surface as viewed from above. The evolution of the prominence seen in EUV images taken with the Solar Dynamic Observatory provided us clues to interpret the results as swirling motions. Moreover, time-distance images taken far from the central wavelength show plasma structures moving parallel to the solar limb with ve...

  10. CT-guided percutaneous laser photocoagulation of osteoid osteomas of the hands and feet

    Energy Technology Data Exchange (ETDEWEB)

    Zouari, Leila; Bousson, Valerie; Hamze, Bassam; Roqueplan, Francois; Laredo, Jean-Denis [Hopital Lariboisiere, Service de Radiologie Osteo-Articulaire, Paris (France); Roulot, Eric [Clinique Jouvenet, Institut de la main, Paris (France)

    2008-11-15

    Percutaneous local ablation of osteoid osteoma has largely replaced surgery, except in the small bones of the hands and feet. The objective of this study was to describe the technical specificities and results of computed tomography (CT)-guided percutaneous laser photocoagulation in 15 patients with osteoid osteomas of the hands and feet. We retrospectively examined the medical charts of the 15 patients who were treated with CT-guided percutaneous laser photocoagulation therapy at our institution between 1994 and 2004. The 15 patients had a mean age of 24.33 years. None of them had received any prior surgical or percutaneous treatment for the osteoid osteoma. The follow-up period was 24 to 96 months (mean, 49.93). The pain resolved completely within 1 week. Fourteen patients remained symptom-free throughout the follow-up period; the remaining patient experienced a recurrence of pain after 24 months, underwent a second laser photocoagulation procedure, and was symptom-free at last follow-up 45 months later. No adverse events related to the procedure or to the location of the tumor in the hand or the foot were recorded. CT-guided percutaneous laser photocoagulation is an alternative to surgery for the treatment of osteoid osteomas of the hands and feet. (orig.)

  11. Segmental kinematic analysis of planovalgus feet during walking in children with cerebral palsy.

    Science.gov (United States)

    Kruger, Karen M; Konop, Katherine A; Krzak, Joseph J; Graf, Adam; Altiok, Haluk; Smith, Peter A; Harris, Gerald F

    2017-05-01

    Pes planovalgus (flatfoot) is a common deformity among children with cerebral palsy. The Milwaukee Foot Model (MFM), a multi-segmental kinematic foot model, which uses radiography to align the underlying bony anatomy with reflective surface markers, was used to evaluate 20 pediatric participants (30feet) with planovalgus secondary to cerebral palsy prior to surgery. Three-dimensional kinematics of the tibia, hindfoot, forefoot, and hallux segments are reported and compared to an age-matched control set of typically-developing children. Most results were consistent with known characteristics of the deformity and showed decreased plantar flexion of the forefoot relative to hindfoot, increased forefoot abduction, and decreased ranges of motion during push-off in the planovalgus group. Interestingly, while forefoot characteristics were uniformly distributed in a common direction in the transverse plane, there was marked variability of forefoot and hindfoot coronal plane and hindfoot transverse plane positioning. The key finding of these data was the radiographic indexing of the MFM was able to show flat feet in cerebral palsy do not always demonstrate more hindfoot eversion than the typically-developing hindfoot. The coronal plane kinematics of the hindfoot show cases planovalgus feet with the hindfoot in inversion, eversion, and neutral. Along with other metrics, the MFM can be a valuable tool for monitoring kinematic deformity, facilitating clinical decision making, and providing a quantitative analysis of surgical effects on the planovalgus foot. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Foot reflexology in feet impairment of people with type 2 diabetes mellitus: randomized trial

    Directory of Open Access Journals (Sweden)

    Natália Chantal Magalhães da Silva

    2015-08-01

    Full Text Available AbstractObjective: to evaluate the effect of foot reflexology on feet impairment of people with type 2 diabetes mellitus.Method: this is a randomized, controlled and blind clinical trial. The sample was comprised by people with type 2 diabetes mellitus who, after being randomized into Treated group (n = 21 and Control group (n = 24, received guidelines on foot self-care. To the Treated Group it was also provided 12 sessions of foot reflexology. The scores of impairment indicators related to skin and hair, blood circulation, tissue sensitivity and temperature were measured by means of the instrument for assessing tissue integrity of the feet of people with diabetes mellitus. Chi-square test, Fisher exact test, Mann-Whitney test and regression analyzes were applied to the data, considering a significance level of 5% (P value <0.05.Results: participants who received the therapy showed better scores in some impairment indicators related to skin and hair (hair growth, elasticity/turgor, hydration, perspiration, texture and integrity of the skin/ skin peeling.Conclusion: the foot reflexology had a beneficial effect on feet impairment of people with type 2 diabetes mellitus, which makes it a viable therapy, deserving investment. This study was registered in the Brazilian Registry of Clinical Trials - RBR-8zk8sz.

  13. Normative data for cutaneous threshold and spatial discrimination in the feet.

    Science.gov (United States)

    Rinkel, Willem D; Aziz, M Hosein; Van Deelen, Meike J M; Willemsen, Sten P; Castro Cabezas, Manuel; Van Neck, Johan W; Coert, J Henk

    2017-09-01

    No data are available for normative values of cutaneous threshold and spatial discrimination in the feet. We developed clinically applicable reference values in relation to the nerve distributions of the feet. We determined foot sensation in 196 healthy individuals. Cutaneous threshold (1-point static discrimination, S1PD) was tested with monofilaments (0.008 to 300 gram) and spatial discrimination (2-point static [S2PD] and moving [M2PD] discrimination) on five locations per foot. There was a significant age-dependent increase in S1PD, S2PD, and M2PD values (P < 0.05). No significant differences were found between both feet. S1PD values differed up to 0.8 g between genders. There were no significant differences between genders for S2PD and M2PD measurements. M2PD values were generally lower than S2PD values. This study provides age-related normative values for foot sensation to help clinicians assess sensory deficits in relation to aging and identify patients with underlying nerve problems. Muscle Nerve 56: 399-407, 2017. © 2016 Wiley Periodicals, Inc.

  14. Cubic ideal ferromagnets at low temperature and weak magnetic field

    Science.gov (United States)

    Hofmann, Christoph P.

    2017-04-01

    The low-temperature series for the free energy density, pressure, magnetization and susceptibility of cubic ideal ferromagnets in weak external magnetic fields are discussed within the effective Lagrangian framework up to three loops. The structure of the simple, body-centered, and face-centered cubic lattice is taken into account explicitly. The expansion involves integer and half-integer powers of the temperature. The corresponding coefficients depend on the magnetic field and on low-energy effective constants that can be expressed in terms of microscopic quantities. Our formulas may also serve as efficiency or consistency check for other techniques like Green's function methods, where spurious terms in the low-temperature expansion have appeared. We explore the sign and magnitude of the spin-wave interaction in the pressure, magnetization and susceptibility, and emphasize that our effective field theory approach is fully systematic and rigorous.

  15. Counting real cubics with passage/tangency conditions

    CERN Document Server

    Lanzat, Sergei

    2010-01-01

    We study the following question: given a set of seven points and an immersed curve in the real plane R^2, all in general position, how many real rational nodal plane cubics pass through these points and are tangent to this curve. We count each such cubic with a certain sign, and present an explicit formula for their algebraic number. This number is preserved under small regular homotopies of the curve, but jumps (in a well-controlled way) when in the process of homotopy we pass a certain singular discriminant. We discuss the relation of such enumerative problems with finite type invariants. Our approach is based on maps of configuration spaces and the intersection theory in the spirit of classical algebraic topology.

  16. Reversible Nanoparticle Cubic Lattices in Blue Phase Liquid Crystals.

    Science.gov (United States)

    Gharbi, Mohamed Amine; Manet, Sabine; Lhermitte, Julien; Brown, Sarah; Milette, Jonathan; Toader, Violeta; Sutton, Mark; Reven, Linda

    2016-03-22

    Blue phases (BPs), a distinct class of liquid crystals (LCs) with 3D periodic ordering of double twist cylinders involving orthogonal helical director twists, have been theoretically studied as potential templates for tunable colloidal crystals. Here, we report the spontaneous formation of thermally reversible, cubic crystal nanoparticle (NP) assemblies in BPs. Gold NPs, functionalized to be highly miscible in cyanobiphenyl-based LCs, were dispersed in BP mixtures and characterized by polarized optical microscopy and synchrotron small-angle X-ray scattering (SAXS). The NPs assemble by selectively migrating to periodic strong trapping sites in the BP disclination lines. The NP lattice, remarkably robust given the small particle size (4.5 nm diameter), is commensurate with that of the BP matrix. At the BP I to BP II phase transition, the NP lattice reversibly switches between two different cubic structures. The simultaneous presence of two different symmetries in a single material presents an interesting opportunity to develop novel dynamic optical materials.

  17. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    KAUST Repository

    Suteewong, Teeraporn

    2011-01-19

    Mesoporous silica with cubic symmetry has attracted interest from researchers for some time. Here, we present the room temperature synthesis of mesoporous silica nanoparticles possessing cubic Pm3n symmetry with very high molar ratios (>50%) of 3-aminopropyl triethoxysilane. The synthesis is robust allowing, for example, co-condensation of organic dyes without loss of structure. By means of pore expander molecules, the pore size can be enlarged from 2.7 to 5 nm, while particle size decreases. Adding pore expander and co-condensing fluorescent dyes in the same synthesis reduces average particle size further down to 100 nm. After PEGylation, such fluorescent aminated mesoporous silica nanoparticles are spontaneously taken up by cells as demonstrated by fluorescence microscopy.

  18. The Piecewise Cubic Method (PCM) for computational fluid dynamics

    Science.gov (United States)

    Lee, Dongwook; Faller, Hugues; Reyes, Adam

    2017-07-01

    We present a new high-order finite volume reconstruction method for hyperbolic conservation laws. The method is based on a piecewise cubic polynomial which provides its solutions a fifth-order accuracy in space. The spatially reconstructed solutions are evolved in time with a fourth-order accuracy by tracing the characteristics of the cubic polynomials. As a result, our temporal update scheme provides a significantly simpler and computationally more efficient approach in achieving fourth order accuracy in time, relative to the comparable fourth-order Runge-Kutta method. We demonstrate that the solutions of PCM converges at fifth-order in solving 1D smooth flows described by hyperbolic conservation laws. We test the new scheme on a range of numerical experiments, including both gas dynamics and magnetohydrodynamics applications in multiple spatial dimensions.

  19. The Piecewise Cubic Method (PCM) for Computational Fluid Dynamics

    CERN Document Server

    Lee, Dongwook; Reyes, Adam

    2016-01-01

    We present a new high-order finite volume reconstruction method for hyperbolic conservation laws. The method is based on a piecewise cubic polynomial which provides its solutions a fifth-order accuracy in space. The spatially reconstructed solutions are evolved in time with a fourth-order accuracy by tracing the characteristics of the cubic polynomials. As a result, our temporal update scheme provides a significantly simpler and computationally more efficient approach in achieving fourth order accuracy in time, relative to the comparable fourth-order Runge-Kutta method. We demonstrate that the solutions of PCM converges in fifth-order in solving 1D smooth flows described by hyperbolic conservation laws. We test the new scheme in a range of numerical experiments, including both gas dynamics and magnetohydrodynamics applications in multiple spatial dimensions.

  20. Cubic Composite Sensor with Photodiodes for Tracking Solar Orientation

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2013-01-01

    Full Text Available A cubic composite solar sensor with photo diode is proposed for tracking the relative solar orientation. The proposed solar sensor composes of five photodiode detectors which are placed on the front, rear, left, right, and horizontal facets in a cubic body, respectively. The solar detectors placed on five facets can detect solar power of different facets. Based on the geometric coordinate transformation principle, the relationship equations of solar light orientation between measured powers with respect to various facets can be conducted. As a result, the solar orientation can be precisely achieved without needing any assistance of electronic compass and extra orientation angle corrector. Eventually, the relative solar light orientation, the elevation angle, and azimuth angle of the solar light can be measured precisely.

  1. Nonlinear optical imaging of defects in cubic silicon carbide epilayers.

    Science.gov (United States)

    Hristu, Radu; Stanciu, Stefan G; Tranca, Denis E; Matei, Alecs; Stanciu, George A

    2014-06-11

    Silicon carbide is one of the most promising materials for power electronic devices capable of operating at extreme conditions. The widespread application of silicon carbide power devices is however limited by the presence of structural defects in silicon carbide epilayers. Our experiment demonstrates that optical second harmonic generation imaging represents a viable solution for characterizing structural defects such as stacking faults, dislocations and double positioning boundaries in cubic silicon carbide layers. X-ray diffraction and optical second harmonic rotational anisotropy were used to confirm the growth of the cubic polytype, atomic force microscopy was used to support the identification of silicon carbide defects based on their distinct shape, while second harmonic generation microscopy revealed the detailed structure of the defects. Our results show that this fast and noninvasive investigation method can identify defects which appear during the crystal growth and can be used to certify areas within the silicon carbide epilayer that have optimal quality.

  2. Global Sufficient Optimality Conditions for a Special Cubic Minimization Problem

    Directory of Open Access Journals (Sweden)

    Xiaomei Zhang

    2012-01-01

    Full Text Available We present some sufficient global optimality conditions for a special cubic minimization problem with box constraints or binary constraints by extending the global subdifferential approach proposed by V. Jeyakumar et al. (2006. The present conditions generalize the results developed in the work of V. Jeyakumar et al. where a quadratic minimization problem with box constraints or binary constraints was considered. In addition, a special diagonal matrix is constructed, which is used to provide a convenient method for justifying the proposed sufficient conditions. Then, the reformulation of the sufficient conditions follows. It is worth noting that this reformulation is also applicable to the quadratic minimization problem with box or binary constraints considered in the works of V. Jeyakumar et al. (2006 and Y. Wang et al. (2010. Finally some examples demonstrate that our optimality conditions can effectively be used for identifying global minimizers of the certain nonconvex cubic minimization problem.

  3. Plasma simulation with the Differential Algebraic Cubic Interpolated Propagation scheme

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Takayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    A computer code based on the Differential Algebraic Cubic Interpolated Propagation scheme has been developed for the numerical solution of the Boltzmann equation for a one-dimensional plasma with immobile ions. The scheme advects the distribution function and its first derivatives in the phase space for one time step by using a numerical integration method for ordinary differential equations, and reconstructs the profile in phase space by using a cubic polynomial within a grid cell. The method gives stable and accurate results, and is efficient. It is successfully applied to a number of equations; the Vlasov equation, the Boltzmann equation with the Fokker-Planck or the Bhatnagar-Gross-Krook (BGK) collision term and the relativistic Vlasov equation. The method can be generalized in a straightforward way to treat cases such as problems with nonperiodic boundary conditions and higher dimensional problems. (author)

  4. Quantum spectra and classical periodic orbit in the cubic billiard

    Institute of Scientific and Technical Information of China (English)

    Dehua Wang; Yongjiang Yu; Shenglu Lin

    2006-01-01

    Quantum billiards have attracted much interest in many fields. People have made a lot of researches on the two-dimensional (2D) billiard systems. Contrary to the 2D billiard, due to the complication of its classical periodic orbits, no one has studied the correspondence between the quantum spectra and the classical orbits of the three-dimensional (3D) billiards. Taking the cubic billiard as an example, using the periodic orbit theory, we find the periodic orbit of the cubic billiard and study the correspondence between the quantum spectra and the length of the classical orbits in 3D system. The Fourier transformed spectrum of this system has allowed direct comparison between peaks in such plot and the length of the periodic orbits, which verifies the correctness of the periodic orbit theory. This is another example showing that semiclassical method provides a bridge between quantum and classical mechanics.

  5. Quantum Phase Transitions in Anti-ferromagnetic Planar Cubic Lattices

    CERN Document Server

    Wellard, C J; Wellard, Cameron; Orus, Roman

    2004-01-01

    Motivated by its relation to an NP-hard problem we analyze the ground state properties of anti-ferromagnetic Ising-spin networks in planar cubic lattices under the action of homogeneous transverse and longitudinal magnetic fields. We consider different instances of the cubic geometry and find a set of quantum phase transitions for each one of the systems, which we characterize by means of entanglement behavior and majorization theory. Entanglement scaling at the critical region is in agreement with results arising from conformal symmetry, therefore even the simplest planar systems can display very large amounts of quantum correlation. No conclusion can be made as to the scaling behavior of the minimum energy gap, with the data allowing equally good fits to exponential and power law decays. Analysis of entanglement and especially of majorization instead of the energy spectrum proves to be a good way of detecting quantum phase transitions in highly frustrated configurations.

  6. Higher-Order Approximation of Cubic-Quintic Duffing Model

    DEFF Research Database (Denmark)

    Ganji, S. S.; Barari, Amin; Babazadeh, H.

    2011-01-01

    We apply an Artificial Parameter Lindstedt-Poincaré Method (APL-PM) to find improved approximate solutions for strongly nonlinear Duffing oscillations with cubic-quintic nonlinear restoring force. This approach yields simple linear algebraic equations instead of nonlinear algebraic equations...... without analytical solution which makes it a unique solution. It is demonstrated that this method works very well for the whole range of parameters in the case of the cubic-quintic oscillator, and excellent agreement of the approximate frequencies with the exact one has been observed and discussed....... Moreover, it is not limited to the small parameter such as in the classical perturbation method. Interestingly, this study revealed that the relative error percentage in the second-order approximate analytical period is less than 0.042% for the whole parameter values. In addition, we compared...

  7. 3D Medical Image Interpolation Based on Parametric Cubic Convolution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the process of display, manipulation and analysis of biomedical image data, they usually need to be converted to data of isotropic discretization through the process of interpolation, while the cubic convolution interpolation is widely used due to its good tradeoff between computational cost and accuracy. In this paper, we present a whole concept for the 3D medical image interpolation based on cubic convolution, and the six methods, with the different sharp control parameter, which are formulated in details. Furthermore, we also give an objective comparison for these methods using data sets with the different slice spacing. Each slice in these data sets is estimated by each interpolation method and compared with the original slice using three measures: mean-squared difference, number of sites of disagreement, and largest difference. According to the experimental results, we present a recommendation for 3D medical images under the different situations in the end.

  8. Experimental core electron density of cubic boron nitride

    DEFF Research Database (Denmark)

    Wahlberg, Nanna; Bindzus, Niels; Bjerg, Lasse

    candidate because of its many similarities with diamond: bonding pattern in the extended network structure, hardness, and the quality of the crystallites.3 However, some degree ionic interaction is a part of the bonding in boron nitride, which is not present in diamond. By investigating the core density...... beyond multipolar modeling of the valence density. As was recently shown in a benchmark study of diamond by Bindzus et al.1 The next step is to investigate more complicated chemical bonding motives, to determine the effect of bonding on the core density. Cubic boron nitride2 lends itself as a perfect...... in boron nitride we may obtain a deeper understanding of the effect of bonding on the total density. We report here a thorough investigation of the charge density of cubic boron nitride with a detailed modelling of the inner atom charge density. By combining high resolution powder X-ray diffraction data...

  9. Quadratic and Cubic Nonlinear Oscillators with Damping and Their Applications

    Science.gov (United States)

    Li, Jibin; Feng, Zhaosheng

    We apply the qualitative theory of dynamical systems to study exact solutions and the dynamics of quadratic and cubic nonlinear oscillators with damping. Under certain parametric conditions, we also consider the van der Waals normal form, Chaffee-Infante equation, compound Burgers-KdV equation and Burgers-KdV equation for explicit representations of kink-profile wave solutions and unbounded traveling wave solutions.

  10. The Number of Real Roots of a Cubic Equation

    Science.gov (United States)

    Kavinoky, Richard; Thoo, John B.

    2008-01-01

    To find the number of distinct real roots of the cubic equation (1) x[caret]3 + bx[caret]2 + cx + d = 0, we could attempt to solve the equation. Fortunately, it is easy to tell the number of distinct real roots of (1) without having to solve the equation. The key is the discriminant. The discriminant of (1) appears in Cardan's (or Cardano's) cubic…

  11. A highly ordered cubic mesoporous silica/graphene nanocomposite

    Science.gov (United States)

    Lee, Chang-Wook; Roh, Kwang Chul; Kim, Kwang-Bum

    2013-09-01

    A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites.A highly ordered cubic mesoporous silica (KIT-6)/graphene nanocomposite and 2D KIT-6 nanoflakes were synthesized using a novel synthesis methodology. The non-ionic triblock copolymer, P123, played a dual role as a structure-directing agent in the formation of the cubic mesoporous structure and as a cross-linking agent between mesoporous silica and graphene. The prepared (KIT-6)/graphene nanocomposite could act as a template for the preparation of mesoporous material/graphene nanocomposites. Electronic supplementary information (ESI) available: S1: TEM images of disordered mesoporous silica/graphene nanocomposite; S2: TEM images of KIT-6/GO nanocomposite; S3: Thermogravimetric analysis of KIT-6/GO and KG-400-700; S4: SEM and TEM images of KIT-6; S5: Low angle XRD, Raman spectra, N2 adsorption isotherms, pore size distribution and photographic images of the prepared samples; S6: TEM image and N2 adsorption isotherms of mesoporous carbon/graphene nanocomposite; S7: XPS C1s spectra of the prepared samples. See DOI: 10.1039/c3nr03108j

  12. Multiscale Modeling of Point and Line Defects in Cubic Lattices

    Science.gov (United States)

    2007-01-01

    and discli- nations with finite micropolar elastoplasticity . Int. J. Plasticity. 22:210–256, 2006. 56. Menzel, A., and Steinmann, P., On the contin...Voyiadjis, G. Z., A finite strain plastic- damage model for high velocity impact using combined viscosity and gradient localization limiters: Part I...Theoretical for- mulation. Int. J. Damage Mech. 15:293–334, 2006. 58. Milstein, F., and Chantasiriwan, S,. Theoretical study of the response of 12 cubic

  13. INTEGRABILITY AND LINEARIZABILITY FOR A CLASS OF CUBIC KOLMOGOROV SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The integrability and linearizability for a class of cubic Kolmogorov systems are studied. A recursive formula to compute the saddle quantities of the systems is deduced firstly, and integrable conditions for the systems are obtained. Then a recursive formula to compute the coefficients of the normal form for saddle points of the systems is also applied. Finally linearizable conditions of the origin for the systems are given. Both formulas to find necessary conditions are all linear and readily done using c...

  14. Photonic Crystal Cavities in Cubic Polytype Silicon Carbide Films

    CERN Document Server

    Radulaski, Marina; Buckley, Sonia; Rundquist, Armand; Provine, J; Alassaad, Kassem; Ferro, Gabriel; Vučković, Jelena

    2013-01-01

    We present the design, fabrication, and characterization of high quality factor and small mode volume planar photonic crystal cavities from cubic (3C) thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1250 - 1600 nm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.

  15. Infinite Body Centered Cubic Network of Identical Resistors

    CERN Document Server

    Asad, J H

    2013-01-01

    We express the equivalent resistance between the origin and any other lattice site in an infinite Body Centered Cubic (BCC) network consisting of identical resistors each of resistance R rationally in terms of known values and . The equivalent resistance is then calculated. Finally, for large separation between the origin and the lattice site two asymptotic formulas for the resistance are presented and some numerical results with analysis are given.

  16. Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography.

    Science.gov (United States)

    Weierstall, Uwe; James, Daniel; Wang, Chong; White, Thomas A; Wang, Dingjie; Liu, Wei; Spence, John C H; Bruce Doak, R; Nelson, Garrett; Fromme, Petra; Fromme, Raimund; Grotjohann, Ingo; Kupitz, Christopher; Zatsepin, Nadia A; Liu, Haiguang; Basu, Shibom; Wacker, Daniel; Han, Gye Won; Katritch, Vsevolod; Boutet, Sébastien; Messerschmidt, Marc; Williams, Garth J; Koglin, Jason E; Marvin Seibert, M; Klinker, Markus; Gati, Cornelius; Shoeman, Robert L; Barty, Anton; Chapman, Henry N; Kirian, Richard A; Beyerlein, Kenneth R; Stevens, Raymond C; Li, Dianfan; Shah, Syed T A; Howe, Nicole; Caffrey, Martin; Cherezov, Vadim

    2014-01-01

    Lipidic cubic phase (LCP) crystallization has proven successful for high-resolution structure determination of challenging membrane proteins. Here we present a technique for extruding gel-like LCP with embedded membrane protein microcrystals, providing a continuously renewed source of material for serial femtosecond crystallography. Data collected from sub-10-μm-sized crystals produced with less than 0.5 mg of purified protein yield structural insights regarding cyclopamine binding to the Smoothened receptor.

  17. Rotary Ultrasonic Machining of Poly-Crystalline Cubic Boron Nitride

    OpenAIRE

    2014-01-01

    Poly-crystalline cubic boron nitride (PCBN) is one of the hardest material. Generally, so hard materials could not be machined by conventional machining methods. Therefore, for this purpose, advanced machining methods have been designed. Rotary ultrasonic machining (RUM) is included among them. RUM is based on abrasive removing mechanism of ultrasonic vibrating diamond particles, which are bonded on active part of rotating tool. It is suitable especially for machining hard and brittle materia...

  18. Bicontinuous cubic liquid crystalline nanoparticles for oral delivery of Doxorubicin

    DEFF Research Database (Denmark)

    Swarnakar, Nitin K; Thanki, Kaushik; Jain, Sanyog

    2014-01-01

    PURPOSE: The present study explores the potential of bicontinous cubic liquid crystalline nanoparticles (LCNPs) for improving therapeutic potential of doxorubicin. METHODS: Phytantriol based Dox-LCNPs were prepared using hydrotrope method, optimized for various formulation components, process...... variables and lyophilized. Structural elucidation of the reconstituted formulation was performed using HR-TEM and SAXS analysis. The developed formulation was subjected to exhaustive cell culture experiments for delivery potential (Caco-2 cells) and efficacy (MCF-7 cells). Finally, in vivo pharmacokinetics...

  19. The traveling salesman problem on cubic and subcubic graphs

    CERN Document Server

    Boyd, Sylvia; van der Ster, Suzanne; Stougie, Leen

    2011-01-01

    We study the Travelling Salesman Problem (TSP) on the metric completion of cubic and subcubic graphs, which is known to be NP-hard. The problem is of interest because of its relation to the famous 4/3 conjecture for metric TSP, which says that the integrality gap, i.e., the worst case ratio between the optimal values of the TSP and its linear programming relaxation (the subtour elimination relaxation), is 4/3. We present the first algorithm for cubic graphs with approximation ratio 4/3. The proof uses polyhedral techniques in a surprising way, which is of independent interest. In fact we prove constructively that for any cubic graph on $n$ vertices a tour of length 4n/3-2 exists, which also implies the 4/3 conjecture, as an upper bound, for this class of graph-TSP. Recently, M\\"omke and Svensson presented a randomized algorithm that gives a 1.461-approximation for graph-TSP on general graphs and as a side result a 4/3-approximation algorithm for this problem on subcubic graphs, also settling the 4/3 conjectur...

  20. Field-effect transistors based on cubic indium nitride.

    Science.gov (United States)

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-02-04

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics.

  1. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics.

    Science.gov (United States)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO_{2} sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016)2045-232210.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  2. Dry Powder Precursors of Cubic Liquid Crystalline Nanoparticles (cubosomes)

    Science.gov (United States)

    Spicer, Patrick T.; Small, William B.; Small, William B.; Lynch, Matthew L.; Burns, Janet L.

    2002-08-01

    Cubosomes are dispersed nanostructured particles of cubic phase liquid crystal that have stimulated significant research interest because of their potential for application in controlled-release and drug delivery. Despite the interest, cubosomes can be difficult to fabricate and stabilize with current methods. Most of the current work is limited to liquid phase processes involving high shear dispersion of bulk cubic liquid crystalline material into sub-micron particles, limiting application flexibility. In this work, two types of dry powder cubosome precursors are produced by spray-drying: (1) starch-encapsulated monoolein is produced by spray-drying a dispersion of cubic liquid crystalline particles in an aqueous starch solution and (2) dextran-encapsulated monoolein is produced by spray-drying an emulsion formed by the ethanol-dextran-monoolein-water system. The encapsulants are used to decrease powder cohesion during drying and to act as a soluble colloidal stabilizer upon hydration of the powders. Both powders are shown to form (on average) 0.6 μm colloidally-stable cubosomes upon addition to water. However, the starch powders have a broader particle size distribution than the dextran powders because of the relative ease of spraying emulsions versus dispersions. The developed processes enable the production of nanostructured cubosomes by end-users rather than just specialized researchers and allow tailoring of the surface state of the cubosomes for broader application.

  3. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics

    Science.gov (United States)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO2 sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016), 10.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  4. Integer roots of quadratic and cubic polynomials with integer coefficients

    CERN Document Server

    Zelator, Konstantine

    2011-01-01

    The subject matter of this work is quadratic and cubic polynomial functions with integer coefficients;and all of whose roots are integers. The material of this work is directed primarily at educators,students,and teachers of mathematics,grades K12 to K20.The results of this work are expressed in Theorems3,4,and5. Of these theorems, Theorem3, is the one that most likely, the general reader of this article will have some familiarity with.In Theorem3, precise coefficient conditions are given;in order that a quadratic trinomial(with integer) have two integer roots or zeros.On the other hand, Theorems4 and5 are largely unfamiliar territory. In Theorem4, precise coefficient conditions are stated; for a monic cubic polynomial to have a double(i.e.of multiplicity 2) integer root, and a single integer root(i.e.of multiplicity 1).The entire family of such cubics can be described in terms of four groups or subfamilies; each such group being a two-integer parameter subfamily. In Theorem5, a one-integer parameter family o...

  5. Arithmetic Problems in Cubic and Quartic Function Fields

    CERN Document Server

    Bembom, Tobias

    2010-01-01

    One of the main themes in this thesis is the description of the signature of both the infinite place and the finite places in cubic function fields of any characteristic and quartic function fields of characteristic at least 5. For these purposes, we provide a new theory which can be applied to cubic and quartic function fields and to even higher dimensional function fields. One of the striking advantages of this theory to other existing methods is that is does not use the concept of p-adic completions and we can dispense of Cardano's formulae. Another key result comprises the construction of cubic function fields of unit rank 1 and 2, with an obvious fundamental system. One of the main ingredients for such constructions is the definition of the maximum value. This definition is new and very prolific in the context of finding fundamental systems. We conclude the thesis with miscellaneous results on the divisor class number h, including a new approach for finding divisors of h.

  6. Dynamic properties of the cubic nonlinear Schr(o)dinger equation by symplectic method

    Institute of Scientific and Technical Information of China (English)

    Liu Xue-Shen; Wei Jia-Yu; Ding Pei-Zhu

    2005-01-01

    The dynamic properties of a cubic nonlinear Schrodinger equation are investigated numerically by using the symplectic method with different space approximations. The behaviours of the cubic nonlinear Schrodinger equation are discussed with different cubic nonlinear parameters in the harmonically modulated initial condition. We show that the conserved quantities will be preserved for long-time computation but the system will exhibit different dynamic behaviours in space difference approximation for the strong cubic nonlinearity.

  7. Sex differences in relative foot length and perceived attractiveness of female feet: relationships among anthropometry, physique, and preference ratings.

    Science.gov (United States)

    Voracek, Martin; Fisher, Maryanne L; Rupp, Barbara; Lucas, Deanna; Fessler, Daniel M T

    2007-06-01

    Foot size proportionate to stature is smaller in women than in men, and small feet apparently contribute to perceived physical attractiveness of females. This exploratory study investigated the sex difference in relative foot length and interrelations among foot length, physique, and foot preference ratings in samples from Austria and Canada, each comprised of 75 men and 75 women. The findings included the following lines of evidence: the sex difference in relative foot length replicated in both data sets; the magnitude of this sex effect was large. Relative foot length was smaller in young, nulliparous, and slim women. Pointed-toe and high-heel shoes were more likely worn by smaller, lighter, and slimmer women. Men reported liking women's feet in general more than vice versa. A vast majority of both men and women favored small feet in women, but large feet in men. One's own foot size appeared to correspond to evaluations of attractiveness; particularly, women with small feet preferred small feet in women in general. The preference for small feet in women was convergent across different methods of evaluating attractiveness. Directions for investigations in this emerging field of research on physical attractiveness are discussed.

  8. Development of the long bones in the hands and feet of children: radiographic and MR imaging correlation

    Energy Technology Data Exchange (ETDEWEB)

    Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Clarke, Jeffrey P. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Children' s Healthcare of Atlanta, Department of Radiology, Atlanta, GA (United States); Yin, Hong [Children' s Healthcare of Atlanta, Department of Pathology, Atlanta, GA (United States)

    2016-04-15

    The long bones of the hands and feet in children have an epiphyseal end with a secondary center of ossification and an adjacent transverse physis. In contrast to other long bones in the body, the opposite end in the hands and feet, termed the non-epiphyseal end, is characterized by direct metaphyseal extension of bone to complete terminal ossification. The purpose of this pictorial essay is to illustrate the developmental stages of each end of the long bones of the hands and feet with radiographic and MR imaging to provide a foundation from which to differentiate normal from abnormal growth. (orig.)

  9. Flat feet, happy feet? Comparison of the dynamic plantar pressure distribution and static medial foot geometry between Malawian and Dutch adults.

    Directory of Open Access Journals (Sweden)

    Niki M Stolwijk

    Full Text Available In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA. We found that Malawian adults: (1 loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2 had significantly lower plantar pressures under the heel and a part of the forefoot, and (3 had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints.

  10. Flat feet, happy feet? Comparison of the dynamic plantar pressure distribution and static medial foot geometry between Malawian and Dutch adults.

    Science.gov (United States)

    Stolwijk, Niki M; Duysens, Jacques; Louwerens, Jan Willem K; van de Ven, Yvonne Hm; Keijsers, Noël Lw

    2013-01-01

    In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI) and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA). We found that Malawian adults: (1) loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2) had significantly lower plantar pressures under the heel and a part of the forefoot, and (3) had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints.

  11. The structure of the cushions in the feet of African elephants (Loxodonta africana).

    Science.gov (United States)

    Weissengruber, G E; Egger, G F; Hutchinson, J R; Groenewald, H B; Elsässer, L; Famini, D; Forstenpointner, G

    2006-12-01

    The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

  12. Skeletal pathology and variable anatomy in elephant feet assessed using computed tomography

    Directory of Open Access Journals (Sweden)

    Sophie Regnault

    2017-01-01

    Full Text Available Foot problems are a major cause of morbidity and mortality in elephants, but are underreported due to difficulties in diagnosis, particularly of conditions affecting the bones and internal structures. Here we evaluate post-mortem computer tomographic (CT scans of 52 feet from 21 elephants (seven African Loxodonta africana and 14 Asian Elephas maximus, describing both pathology and variant anatomy (including the appearance of phalangeal and sesamoid bones that could be mistaken for disease. We found all the elephants in our study to have pathology of some type in at least one foot. The most common pathological changes observed were bone remodelling, enthesopathy, osseous cyst-like lesions, and osteoarthritis, with soft tissue mineralisation, osteitis, infectious osteoarthriti, subluxation, fracture and enostoses observed less frequently. Most feet had multiple categories of pathological change (81% with two or more diagnoses, versus 10% with a single diagnosis, and 9% without significant pathology. Much of the pathological change was focused over the middle/lateral digits, which bear most weight and experience high peak pressures during walking. We found remodelling and osteoarthritis to be correlated with increasing age, more enthesopathy in Asian elephants, and more cyst-like lesions in females. We also observed multipartite, missing and misshapen phalanges as common and apparently incidental findings. The proximal (paired sesamoids can appear fused or absent, and the predigits (radial/tibial sesamoids can be variably ossified, though are significantly more ossified in Asian elephants. Our study reinforces the need for regular examination and radiography of elephant feet to monitor for pathology and as a tool for improving welfare.

  13. Skeletal pathology and variable anatomy in elephant feet assessed using computed tomography

    Science.gov (United States)

    Dixon, Jonathon J.I.; Warren-Smith, Chris; Hutchinson, John R.; Weller, Renate

    2017-01-01

    Foot problems are a major cause of morbidity and mortality in elephants, but are underreported due to difficulties in diagnosis, particularly of conditions affecting the bones and internal structures. Here we evaluate post-mortem computer tomographic (CT) scans of 52 feet from 21 elephants (seven African Loxodonta africana and 14 Asian Elephas maximus), describing both pathology and variant anatomy (including the appearance of phalangeal and sesamoid bones) that could be mistaken for disease. We found all the elephants in our study to have pathology of some type in at least one foot. The most common pathological changes observed were bone remodelling, enthesopathy, osseous cyst-like lesions, and osteoarthritis, with soft tissue mineralisation, osteitis, infectious osteoarthriti, subluxation, fracture and enostoses observed less frequently. Most feet had multiple categories of pathological change (81% with two or more diagnoses, versus 10% with a single diagnosis, and 9% without significant pathology). Much of the pathological change was focused over the middle/lateral digits, which bear most weight and experience high peak pressures during walking. We found remodelling and osteoarthritis to be correlated with increasing age, more enthesopathy in Asian elephants, and more cyst-like lesions in females. We also observed multipartite, missing and misshapen phalanges as common and apparently incidental findings. The proximal (paired) sesamoids can appear fused or absent, and the predigits (radial/tibial sesamoids) can be variably ossified, though are significantly more ossified in Asian elephants. Our study reinforces the need for regular examination and radiography of elephant feet to monitor for pathology and as a tool for improving welfare. PMID:28123909

  14. Design of a New Propulsion Mechanism of Imitating Duck’s Webbed-feet

    Directory of Open Access Journals (Sweden)

    Yuan Dai

    2013-08-01

    Full Text Available With the wide application of the underwater vehicle in ocean exploration, bionics propulsion aroused intensive interest among researchers. Bionic locomotion of aquatic animals has the advantages of highly maneuver, power-efficient endurance and so on. In the paper the mechanism of duck’s swimming is studied and a novel bionics propulsion mechanism is designed and analyzed. The mechanics of underwater vehicle is investigated by ADAMS. Dynamics response of the system is analyzed by using numerical method. The simulation results suggest that the designed propulsion mechanism can imitate the movement modes of the duck’s webbed feet, and implement the motion of vehicle in fluid environment.

  15. Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of

    Science.gov (United States)

    1979-01-01

    Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of earth's moon, is apparently covered by water ice, as indicated by ground spectrometers and its brightness. In this view, global scale dark sreaks discovered by Voyager 1 that criss-cross the the satelite are becoming visible. Bright rayed impact craters, which are abundant on Ganymede and Callisto, would be easily visible at this range, suggesting that Europa's surface is young and that the streaks are reflections of currently active internal dynamic processes.

  16. Extracting Tree Height from Repeat-Pass PolInSAR Data : Experiments with JPL and ESA Airborne Systems

    Science.gov (United States)

    Lavalle, Marco; Ahmed, Razi; Neumann, Maxim; Hensley, Scott

    2013-01-01

    In this paper we present our latest developments and experiments with the random-motion-over-ground (RMoG) model used to extract canopy height and other important forest parameters from repeat-pass polarimetricinterferometric SAR (Pol-InSAR) data. More specifically, we summarize the key features of the RMoG model in contrast with the random-volume-over-ground (RVoG) model, describe in detail a possible inversion scheme for the RMoG model and illustrate the results of the RMoG inversion using airborne data collected by the Jet Propulsion Laboratory (JPL) and the European Space Agency (ESA).

  17. Extracting Tree Height from Repeat-Pass PolInSAR Data : Experiments with JPL and ESA Airborne Systems

    Science.gov (United States)

    Lavalle, Marco; Ahmed, Razi; Neumann, Maxim; Hensley, Scott

    2013-01-01

    In this paper we present our latest developments and experiments with the random-motion-over-ground (RMoG) model used to extract canopy height and other important forest parameters from repeat-pass polarimetricinterferometric SAR (Pol-InSAR) data. More specifically, we summarize the key features of the RMoG model in contrast with the random-volume-over-ground (RVoG) model, describe in detail a possible inversion scheme for the RMoG model and illustrate the results of the RMoG inversion using airborne data collected by the Jet Propulsion Laboratory (JPL) and the European Space Agency (ESA).

  18. Evaluation of JPL Version-5.9.12 Temperature Profiles, Ocean Skin Temperature, Surface Emissivity, and Cloud Cleared Radiances

    Science.gov (United States)

    Susskind, Joel; Blaisdell, John; Iredell, Lena

    2011-01-01

    Slide presentation discusses: (1) Modifications to JPL 5.9.12 compared to V5.9.1, (2) Some results showing that V5.9.12 O, with original water vapor sounding channels, is preferable to V5.9.12 N with Antonia Gambacorta s new water vapor channels. (3) Comparison of V5.9.12, V5.9.12 AO, V5.9.1, and V5.0, (4) Accuracy and yield of channel by channel Quality Controlled clear-column radiances R(sub i) and (5) Plans for Version-7.

  19. Photographer : JPL Range : 1.5 million km ( 930,000 miles ) This high resolution view of Jupitor's

    Science.gov (United States)

    1979-01-01

    Photographer : JPL Range : 1.5 million km ( 930,000 miles ) This high resolution view of Jupitor's ring, part of a set obtained by Voyager 2 (A79-7101), suggests that it may be divided into several components, as are the rings of Saturn. Seen within the inner edge of the brighter ring is a fainter ring, which may extend all the way down to Jupiter's cloud tops. The ring was unexpectedly bright, due to forward scattering of sunlight by small ring particles. The rings were discovered in March 1979 by Voyager 1.

  20. Quantitative estimation of the state of vault feet gymnasts on the different stages of the long-term training

    Directory of Open Access Journals (Sweden)

    Makarova O.V.

    2013-10-01

    Full Text Available The analysis of the vaults given about the state is conducted feet gymnasts on the different stages of the long-term training. 93 sportswomen of different qualification took part in research. The system of Big foot was used. It is set that on the early stages of the long-term training for gymnasts observed flattening heights of unevenness of navicular bone above the floor. With growth of qualification of sportswomen to avoid development of pathological changes of vaults feet actually not possibly. It is conditioned the rules of competitions to complication of competition compositions and technique of execution of elements of calisthenics. It is marked that appearance of flattening feet requires: corrections in the system of training; introduction of the specially developed methods on the removal of existent deformations; prophylaxis of flat-footedness; strengthening of musculoskeletal system feet.

  1. Vacancy-induced mechanical stabilization of cubic tungsten nitride

    Science.gov (United States)

    Balasubramanian, Karthik; Khare, Sanjay; Gall, Daniel

    2016-11-01

    First-principles methods are employed to determine the structural, mechanical, and thermodynamic reasons for the experimentally reported cubic WN phase. The defect-free rocksalt phase is both mechanically and thermodynamically unstable, with a negative single crystal shear modulus C44=-86 GPa and a positive enthalpy of formation per formula unit Hf=0.623 eV with respect to molecular nitrogen and metallic W. In contrast, WN in the NbO phase is stable, with C44=175 GPa and Hf=-0.839 eV . A charge distribution analysis reveals that the application of shear strain along [100] in rocksalt WN results in an increased overlap of the t2 g orbitals which causes electron migration from the expanded to the shortened W-W bond axes, yielding a negative shear modulus due to an energy reduction associated with new bonding states 8.1-8.7 eV below the Fermi level. A corresponding shear strain in WN in the NbO phase results in an energy increase and a positive shear modulus. The mechanical stability transition from the NaCl to the NbO phase is explored using supercell calculations of the NaCl structure containing Cv=0 %-25 % cation and anion vacancies, while keeping the N-to-W ratio constant at unity. The structure is mechanically unstable for Cvconcentration, the isotropic elastic modulus E of cubic WN is zero, but increases steeply to E =445 GPa for Cv=10 % , and then less steeply to E =561 GPa for Cv=25 % . Correspondingly, the hardness estimated using Tian's model increases from 0 to 15 to 26 GPa as Cv increases from 5% to 10% to 25%, indicating that a relatively small vacancy concentration stabilizes the cubic WN phase and that the large variations in reported mechanical properties of WN can be attributed to relatively small changes in Cv.

  2. Cubic Phases, Cubosomes and Ethosomes for Cutaneous Application.

    Science.gov (United States)

    Esposito, Elisabetta; Drechsler, Markus; Nastruzzi, Claudio; Cortesi, Rita

    2016-01-01

    Cutaneous administration represents a good strategy to treat skin diseases, avoiding side effects related to systemic administration. Apart from conventional therapy, based on the use of semi-solid formulation such as gel, ointments and creams, recently the use of specialized delivery systems based on lipid has been taken hold. This review provides an overview about the use of cubic phases, cubosomes and ethosomes, as lipid systems recently proposed to treat skin pathologies. In addition in the final part of the review cubic phases, cubosomes and ethosomes are compared to solid lipid nanoparticles and lecithin organogel with respect to their potential as delivery systems for cutaneous application. It has been reported that lipid nanosystems are able to dissolve and deliver active molecules in a controlled fashion, thereby improving their bioavailability and reducing side-effects. Particularly lipid matrixes are characterized by skin affinity and biocompatibility allowing their application on skin. Indeed, after cutaneous administration, the lipid matrix of cubic phases and cubosomes coalesces with the lipids of the stratum comeum and leads to the formation of a lipid depot from which the drug associated to the nanosystem can be released in the deeper skin strata in a controlled manner. Ethosomes are characterized by a malleable structure that promotes their interaction with skin, improving their potential as skin delivery systems with respect to liposomes. Also in the case of solid lipid nanoparticles it has been suggested a deep interaction between lipid matrix and skin strata that endorses sustained and prolonged drug release. Concerning lecithin organogel, the peculiar structure of this system, where lecithin exerts a penetration enhancer role, allows a deep interaction with skin strata, promoting the transdermal absorption of the encapsulated drugs.

  3. Comparison of plantar pressure distribution in subjects with normal and flat feet during gait

    Directory of Open Access Journals (Sweden)

    Aluisio Otavio Vargas Avila

    2010-06-01

    Full Text Available The aim of this study was to determine the possible relationship between loss of thenormal medial longitudinal arch measured by the height of the navicular bone in a static situationand variables related to plantar pressure distribution measured in a dynamic situation. Elevenmen (21 ± 3 years, 74 ± 10 kg and 175 ± 4 cm participated in the study. The Novel Emed-ATSystem was used for the acquisition of plantar pressure distribution data (peak pressure, meanpressure, contact area, and relative load at a sampling rate of 50 Hz. The navicular drop testproposed by Brody (1982 was used to assess the height of the navicular bone for classificationof the subjects. The results were compared by the Mann-Whitney U test, with the level of significanceset at p ≤ 0.05. Differences were observed between the two groups in the mid-foot regionfor all variables studied, with the observation of higher mean values in subjects with flat feet.There were also significant differences in contact area, relative load, peak pressure, and meanpressure between groups. The present study demonstrates the importance of paying attentionto subjects with flat feet because changes in plantar pressure distribution are associated withdiscomfort and injuries.

  4. Precise and feasible measurements of lateral calcaneal lengthening osteotomies by radiostereometric analysis in cadaver feet

    Science.gov (United States)

    Martinkevich, P.; Rahbek, O.; Møller-Madsen, B.; Søballe, K.; Stilling, M.

    2015-01-01

    Objectives Lengthening osteotomies of the calcaneus in children are in general grafted with bone from the iliac crest. Artificial bone grafts have been introduced, however, their structural and clinical durability has not been documented. Radiostereometric analysis (RSA) is a very accurate and precise method for measurements of rigid body movements including the evaluation of joint implant and fracture stability, however, RSA has not previously been used in clinical studies of calcaneal osteotomies. We assessed the precision of RSA as a measurement tool in a lateral calcaneal lengthening osteotomy (LCLO). Methods LCLO was performed in six fixed adult cadaver feet. Tantalum markers were inserted on each side of the osteotomy and in the cuboideum. Lengthening was done with a plexiglas wedge. A total of 24 radiological double examinations were obtained. Two feet were excluded due to loose and poorly dispersed markers. Precision was assessed as systematic bias and 95% repeatability limits. Results Systematic bias was generally below 0.10 mm for translations. Precision of migration measurements was below 0.2 mm for translations in the osteotomy. Conclusion RSA is a precise tool for the evaluation of stability in LCLO. Cite this article: Bone Joint Res 2015;4:78–83. PMID:25957380

  5. The Effect of Foot Orthoses on Energy Consumption in Runners with Flat Feet

    Directory of Open Access Journals (Sweden)

    Farzad Farmani

    2010-01-01

    Full Text Available Introduction Foot orthosis is used as protective treatment in people with flatfoot. This study aimed at assessing the effects of Foot orthosis on energy consumption in 20 runners with flat feet.Methods: In this study a treadmill and a Quark b2 were used to measure oxygen consumption. For each patient, a pair of foot orthosis with the appropriate size was prepared. The maximum running Heart rate, vo2 max and vo2 of the subjects were measured and calculated with and without foot orthoses. The data were compared through paired T-test.Results: In this study, after using the foot orthoses, the mean VO2 (ML/M, theVO2 max (ML/M for each Kg of body weight and the maximum heart rate respectively reduced from 4504.6 to 4488.3, from 63.6 to 63.4 and from 168.7 to 168.0, all of which indicating a significant observed reduction (P<0.05.Conclusion: Foot support devices (orthoses result in realignment of lower extremity joints in patients with flat feet, thus length- tension relationship of muscles improve. This prevents muscle fatigue in long- distance running. Finally, when suitable foot orthoses was applied energy consumption during running decreased.

  6. Mapping sea urchins tube feet proteome--a unique hydraulic mechano-sensory adhesive organ.

    Science.gov (United States)

    Santos, Romana; Barreto, Angela; Franco, Catarina; Coelho, Ana Varela

    2013-02-21

    Marine organisms secrete adhesives for substrate attachment that to be effective require functional assembly underwater and displacement of water, ions, and weakly bound polyions that are ubiquitous in seawater. Therefore, understanding the characteristics of these protein/carbohydrate-based marine adhesives is imperative to decipher marine adhesion and also, to accelerate the development of new biomimetic underwater adhesives and anti-fouling agents. The present study, aims at mapping the proteome of the sea urchin Paracentrotus lividus adhesive organs using a combination of complementary protein separation techniques (1-D-nanoLC and 2-DE), databases and search algorithms. This strategy resulted in the identification of 328 non-redundant proteins, constituting the first comprehensive list of sea urchin tube feet proteins. Given the known importance of phosphorylation and glycosylation in marine adhesion, the 2DE proteome was re-analyzed with specific fluorescent stains for these two PTMs, resulting in the identification of 69 non-redundant proteins. The obtained results demonstrate that tube feet are unique mechano-sensory adhesive organs and highlight putative adhesive proteins, that although requiring further confirmation, constitute a step forward in the quest to decipher sea urchins temporary adhesion.

  7. Molecular shifts in limb identity underlie development of feathered feet in two domestic avian species

    Science.gov (United States)

    Domyan, Eric T; Kronenberg, Zev; Infante, Carlos R; Vickrey, Anna I; Stringham, Sydney A; Bruders, Rebecca; Guernsey, Michael W; Park, Sungdae; Payne, Jason; Beckstead, Robert B; Kardon, Gabrielle; Menke, Douglas B; Yandell, Mark; Shapiro, Michael D

    2016-01-01

    Birds display remarkable diversity in the distribution and morphology of scales and feathers on their feet, yet the genetic and developmental mechanisms governing this diversity remain unknown. Domestic pigeons have striking variation in foot feathering within a single species, providing a tractable model to investigate the molecular basis of skin appendage differences. We found that feathered feet in pigeons result from a partial transformation from hindlimb to forelimb identity mediated by cis-regulatory changes in the genes encoding the hindlimb-specific transcription factor Pitx1 and forelimb-specific transcription factor Tbx5. We also found that ectopic expression of Tbx5 is associated with foot feathers in chickens, suggesting similar molecular pathways underlie phenotypic convergence between these two species. These results show how changes in expression of regional patterning genes can generate localized changes in organ fate and morphology, and provide viable molecular mechanisms for diversity in hindlimb scale and feather distribution. DOI: http://dx.doi.org/10.7554/eLife.12115.001 PMID:26977633

  8. Superhydrophobic gecko feet with high adhesive forces towards water and their bio-inspired materials

    Science.gov (United States)

    Liu, Kesong; Du, Jiexing; Wu, Juntao; Jiang, Lei

    2012-01-01

    Functional integration is an inherent characteristic for multiscale structures of biological materials. In this contribution, we first investigate the liquid-solid adhesive forces between water droplets and superhydrophobic gecko feet using a high-sensitivity micro-electromechanical balance system. It was found, in addition to the well-known solid-solid adhesion, the gecko foot, with a multiscale structure, possesses both superhydrophobic functionality and a high adhesive force towards water. The origin of the high adhesive forces of gecko feet to water could be attributed to the high density nanopillars that contact the water. Inspired by this, polyimide films with gecko-like multiscale structures were constructed by using anodic aluminum oxide templates, exhibiting superhydrophobicity and a strong adhesive force towards water. The static water contact angle is larger than 150° and the adhesive force to water is about 66 μN. The resultant gecko-inspired polyimide film can be used as a ``mechanical hand'' to snatch micro-liter liquids. We expect this work will provide the inspiration to reveal the mechanism of the high-adhesive superhydrophobic of geckos and extend the practical applications of polyimide materials.

  9. Validation of a new radiographic protocol for Asian elephant feet and description of their radiographic anatomy.

    Science.gov (United States)

    Mumby, C; Bouts, T; Sambrook, L; Danika, S; Rees, E; Parry, A; Rendle, M; Masters, N; Weller, R

    2013-10-05

    Foot problems are extremely common in elephants and radiography is the only imaging method available but the radiographic anatomy has not been described in detail. The aims of this study were to develop a radiographic protocol for elephant feet using digital radiography, and to describe the normal radiographic anatomy of the Asian elephant front and hind foot. A total of fifteen cadaver foot specimens from captive Asian elephants were radiographed using a range of projections and exposures to determine the best radiographic technique. This was subsequently tested in live elephants in a free-contact setting. The normal radiographic anatomy of the Asian elephant front and hind foot was described with the use of three-dimensional models based on CT reconstructions. The projection angles that were found to be most useful were 65-70° for the front limb and 55-60° in the hind limb. The beam was centred 10-15 cm proximal to the cuticle in the front and 10-15 cm dorsal to the plantar edge of the sole in the hind foot depending on the size of the foot. The protocol developed can be used for larger-scale diagnostic investigations of captive elephant foot disorders, while the normal radiographic anatomy described can improve the diagnostic reliability of elephant feet radiography.

  10. Inflammatory response study of gellan gum impregnated duck's feet derived collagen sponges.

    Science.gov (United States)

    Song, Jeong Eun; Lee, Seon Eui; Cha, Se Rom; Jang, Na Keum; Tripathy, Nirmalya; Reis, Rui L; Khang, Gilson

    2016-10-01

    Tissue engineered biomaterials have biodegradable and biocompatible properties. In this study, we have fabricated sponges using duck's feet derived collagen (DC) and gellan gum (GG), and further studied its inflammatory responses. The as-prepared duck's feet DC/GG sponges showed the possibility of application as a tissue engineering material through in vitro and in vivo experiments. The physical and chemical properties of sponges were characterized by compression strength, porosity, and scanning electron microscopy, etc. In vitro cell viability were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. An inflammatory response was studied after seeding RAW264.7 cells on as-fabricated sponges using reverse transcriptase-polymerase chain reaction. In vivo studies were carried out by implanting in subcutaneous nude mouse followed by extraction, histological staining. Collectively, superior results were showed by DC/GG sponges than GG sponge in terms of physical property and cell proliferation and thus can be considered as a potential candidate for future tissue engineering applications.

  11. Does knee motion contribute to feet-in-place balance recovery?

    Science.gov (United States)

    Cheng, Kuangyou B

    2016-06-14

    Although knee motions have been observed at loss of balance, the ankle and hip strategies have remained the focus of past research. The present study aimed to investigate whether knee motions contribute to feet-in-place balance recovery. This was achieved by experimentally monitoring knee motions during recovery from forward falling, and by simulating balance recovery movements with and without knee joint as the main focus of the study. Twelve participants initially held a straight body configuration and were released from different forward leaning positions. Considerable knee motions were observed especially at greater leaning angles. Simulations were performed using 3-segment (feet, shanks+thighs, and head+arms+trunk) and 4-segment (with separate shanks and thighs segments) planar models. Movements were driven by joint torque generators depending on joint angle, angular velocity, and activation level. Optimal joint motions moved the mass center projection to be within the base of support without excessive joint motion. The 3-segment model (without knee motions) generated greater backward linear momentum and had better balance performance, which confirmed the advantage of having only ankle/hip strategies. Knee motions were accompanied with less body angular momentum and a lower body posture, which could be beneficial for posture control and reducing falling impact, respectively.

  12. Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet

    Directory of Open Access Journals (Sweden)

    Yaguang Zhu

    2016-08-01

    Full Text Available Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system.

  13. Cubature Formula and Interpolation on the Cubic Domain

    Institute of Scientific and Technical Information of China (English)

    Huiyuan Li; Jiachang Sun; Yuan Xu

    2009-01-01

    Several cubature formulas on the cubic domains are derived using the dis-crete Fourier analysis associated with lattice tiling, as developed in [10]. The main results consist of a new derivation of the Gaussian type cubature for the product Cheby-shev weight functions and associated interpolation polynomials on [-1,1]2, as well as new results on [-1,1]3. In particular, compact formulas for the fundamental interpo-lation polynomials are derived, based on n3/4 + (n2) nodes of a cubature formula on [-1,1]3.

  14. CLOSED SMOOTH SURFACE DEFINED FROM CUBIC TRIANGULAR SPLINES

    Institute of Scientific and Technical Information of China (English)

    Ren-zhong Feng; Ren-hong Wang

    2005-01-01

    In order to construct closed surfaces with continuous unit normal, we introduce a new spline space on an arbitrary closed mesh of three-sided faces. Our approach generalizes an idea of Goodman and is based on the concept of 'Geometric continuity' for piecewise polynomial parametrizations. The functions in the spline space restricted to the faces are cubic triangular polynomials. A basis of the spline space is constructed of positive functions which sum to 1. It is also shown that the space is suitable for interpolating data at the midpoints of the faces.

  15. Exotic Universal Solutions in Cubic Superstring Field Theory

    CERN Document Server

    Erler, Theodore

    2010-01-01

    We present a class of analytic solutions of cubic superstring field theory in the universal sector on a non-BPS D-brane. Computation of the action and gauge invariant overlap reveal that the solutions carry half the tension of a non-BPS D-brane. However, the solutions do not satisfy the reality condition. In fact, they display an intriguing topological structure: We find evidence that conjugation of the solutions is equivalent to a gauge transformation that cannot be continuously deformed to the identity.

  16. Research on the Cutting Performance of Cubic Boron Nitride Tools

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    There were only two kinds of superhard tool material at the past, i.e. diamond and cubic boron nitride (CBN). Manmade diamond and CBN are manufactured by the middle of 20th century. Various manufacturing methods and manmade superhard materials were developed later. They were widely used in different industry and science areas. Recently, a new kind of superhard tool material, C 3N 4 coating film, had been developed. American physical scientists, A. M. Liu and M. L. Cohen, designed a new kind of inorganic c...

  17. Self-trapping transition in nonlinear cubic lattices

    CERN Document Server

    Naether, Uta; Guzmán-Silva, Diego; Molina, Mario I; Vicencio, Rodrigo A

    2013-01-01

    We explore the fundamental question about the critical nonlinearity value needed to dynamically localize energy in discrete nonlinear cubic (Kerr) lattices. We focus on the effective frequency and participation ratio of the profile to determine the transition into localization, performing several numerical simulations in one-, two-, and three-dimensional lattices. A simple criterium is developed - for the case of an initially localized excitation - defining the transition region in parameter space ("dynamical tongue") from a delocalized to a localized profile. A general analytical estimate of the critical nonlinearity value for which this transition occurs is obtained.

  18. Cubic versus spherical magnetic nanoparticles: the role of surface anisotropy.

    Science.gov (United States)

    Salazar-Alvarez, G; Qin, J; Sepelák, V; Bergmann, I; Vasilakaki, M; Trohidou, K N; Ardisson, J D; Macedo, W A A; Mikhaylova, M; Muhammed, M; Baró, M D; Nogués, J

    2008-10-08

    The magnetic properties of maghemite (gamma-Fe2O3) cubic and spherical nanoparticles of similar sizes have been experimentally and theoretically studied. The blocking temperature, T(B), of the nanoparticles depends on their shape, with the spherical ones exhibiting larger T(B). Other low temperature properties such as saturation magnetization, coercivity, loop shift or spin canting are rather similar. The experimental effective anisotropy and the Monte Carlo simulations indicate that the different random surface anisotropy of the two morphologies combined with the low magnetocrystalline anisotropy of gamma-Fe2O3 is the origin of these effects.

  19. Configuration spaces of an embedding torus and cubical spaces

    OpenAIRE

    Jourdan, Jean-Philippe

    2006-01-01

    For a smooth manifold M obtained as an embedding torus, A U Cx[-1,1], we consider the ordered configuration space F_k(M) of k distinct points in M. We show that there is a homotopical cubical resolution of F_k(M) defined from the configuration spaces of A and C. From it, we deduce a universal method for the computation of the pure braid groups of a manifold. We illustrate the method in the case of the Mobius band.

  20. Ionic Conduction in Cubic Zirconias at Low Temperatures

    Institute of Scientific and Technical Information of China (English)

    Ying LI; Yunfa CHEN; Jianghong GONG

    2004-01-01

    The ac conductivities of Y2O3 or CaO-stabilized cubic zirconias were obtained from complex impedance measurements in the temperature range from 373 to 473 K. By analyzing the temperature-dependence of the resultant dc conductivities, it was shown that the activation energies for conduction are lower than those reported previously for the same materials at high temperatures. Comparing the activation energy data with the theoretically estimated values revealed that there may exist a certain, although very small, amount of free oxygen vacancies in the test samples at low temperatures and the conduction in the test samples is a result of the migration of these free oxygen vacancies.

  1. Cubic to tetragonal crystal lattice reconstruction during ordering or decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Byung-kl [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering

    1992-09-01

    This thesis studied thermodynamic stability and morphology of product phases in diffusional phase transformations involving cubic-to-tetragonal crystal lattice reconstructions. Two different kinds of diffusional transformations were examined: L1{sub 0} ordering (fcc to fct lattice change) and decomposition of off-stoichiometric B2 ordering alloys accompanying bcc to fcc Bain transformation. In the first case, Fe-45 at.% Pd alloys were studied by TEM; in the second, the Bain strain relaxation during decomposition of hyper-eutectoid Cu-9.04 wt% Be alloy was studied. CuAu and InMg were also studied.

  2. On the {P2, P3}-Factor of Cubic Graphs

    Institute of Scientific and Technical Information of China (English)

    GOU Kui-xiang; SUN Liang

    2005-01-01

    Let G = ( V, E) be a finite simple graph and Pn denote the path of order n. A spanning subgraph F is called a {P2, P3}-factor of G if each component of F is isomorphic to P2 or P3. With the path-covering method, it is proved that any connected cubic graph with at least 5 vertices has a { P2, P3 }-factor F such that | P3 (F) |≥|P2 (F) |, where P2 (F) and P3 (F) denote the set of components of P2 and P3 in F,respectively.

  3. Inhomogeneous atomic Bose-Fermi mixtures in cubic lattices.

    Science.gov (United States)

    Cramer, M; Eisert, J; Illuminati, F

    2004-11-05

    We determine the ground state properties of inhomogeneous mixtures of bosons and fermions in cubic lattices and parabolic confining potentials. For finite hopping we determine the domain boundaries between Mott-insulator plateaux and hopping-dominated regions for lattices of arbitrary dimension within mean-field and perturbation theory. The results are compared with a new numerical method that is based on a Gutzwiller variational approach for the bosons and an exact treatment for the fermions. The findings can be applied as a guideline for future experiments with trapped atomic Bose-Fermi mixtures in optical lattices.

  4. Compressibility and thermal expansion of cubic silicon nitride

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lindelov, H.; Gerward, Leif

    2002-01-01

    The compressibility and thermal expansion of the cubic silicon nitride (c-Si3N4) phase have been investigated by performing in situ x-ray powder-diffraction measurements using synchrotron radiation, complemented with computer simulations by means of first-principles calculations. The bulk...... compressibility of the c-Si3N4 phase originates from the average of both Si-N tetrahedral and octahedral compressibilities where the octahedral polyhedra are less compressible than the tetrahedral ones. The origin of the unit cell expansion is revealed to be due to the increase of the octahedral Si-N and N-N bond...

  5. Theoretical and Experimental Study of Time Reversal in Cubic Crystals

    Institute of Scientific and Technical Information of China (English)

    陆铭慧; 张碧星; 汪承灏

    2004-01-01

    The self-adaptive focusing of the time reversal in anisotropic media is studied theoretically and experimentally. It is conducted for the compressional wave field in the cubic crystal silicon. The experimental result is in agreement with our theoretical analysis. The focusing gain and the displacement distributions of the time reversal field are analysed in detail. It is shown that the waves from different elements of the transducer array arrive at the original place of the source simultaneously after the time reversal operation. The waveform distortions caused by the velocity anisotropy can automatically be compensated for after the time reversal processing.

  6. Rotary Ultrasonic Machining of Poly-Crystalline Cubic Boron Nitride

    Directory of Open Access Journals (Sweden)

    Kuruc Marcel

    2014-12-01

    Full Text Available Poly-crystalline cubic boron nitride (PCBN is one of the hardest material. Generally, so hard materials could not be machined by conventional machining methods. Therefore, for this purpose, advanced machining methods have been designed. Rotary ultrasonic machining (RUM is included among them. RUM is based on abrasive removing mechanism of ultrasonic vibrating diamond particles, which are bonded on active part of rotating tool. It is suitable especially for machining hard and brittle materials (such as glass and ceramics. This contribution investigates this advanced machining method during machining of PCBN.

  7. Cubic Plus Association Equation of State for Flow Assurance Projects

    DEFF Research Database (Denmark)

    dos Santos, Leticia Cotia; Abunahman, Samir Silva; Tavares, Frederico Wanderley

    2015-01-01

    Thermodynamic hydrate inhibitors such as methanol, ethanol, (mono) ethylene glycol (MEG), and triethylene glycol (TEG) are widely used in the oil and gas industry. On modeling these compounds, we show here how the CPA equation of state was implemented in an in-house process simulator as an in......-built model: To validate the implementation, we show calulations for binary systems containing hydrate inhibitors and water or hydrocarbons using the Cubic Plus Association (CPA) and Soave-Redlich-Kwong (SRK) equation of states, also comparing against experimental data. For streams containing natural gas...

  8. Elasticity tensor and ultrasonic velocities for anisotropic cubic polycrystal

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The orientation distribution of crystallites in a polycrystal can be described by the orientation distribution function(ODF) . The ODF can be expanded under the Wigner D-bases. The expanded coefficients in the ODF are called the texture coefficients. In this paper,we use the Clebsch-Gordan expression to derive an explicit expression of the elasticity tensor for an anisotropic cubic polycrystal. The elasticity tensor contains three material constants and nine texture coefficients. In order to measure the nine texture coefficients by ultrasonic wave,we give relations between the nine texture coefficients and ultrasonic propagation velocities. We also give a numerical example to check the relations.

  9. Tensor tomography of stresses in cubic single crystals

    Directory of Open Access Journals (Sweden)

    Dmitry D. Karov

    2015-03-01

    Full Text Available The possibility of optical tomography applying to investigation of a two-dimensional and a three-dimensional stressed state in single cubic crystals has been studied. Stresses are determined within the framework of the Maxwell piezo-optic law (linear dependence of the permittivity tensor on stresses and weak optical anisotropy. It is shown that a complete reconstruction of stresses in a sample is impossible both by translucence it in the parallel planes system and by using of the elasticity theory equations. For overcoming these difficulties, it is offered to use a method of magnetophotoelasticity.

  10. An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study

    Directory of Open Access Journals (Sweden)

    Cejka Caroline

    2012-04-01

    Full Text Available Abstract Background An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii to evaluate a possible association between the changes in plasma sodium concentration ([Na+] and changes in feet volume. Methods In seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography. Results Body mass decreased by 1.8 kg (2.4% (p +] increased by 1.2% (p p = 0.0005. The volume of the feet remained unchanged (p > 0.05. Plasma volume and urine specific gravity increased (p r = 0.54, p +] (r = -0.28, p = 0.0142. Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036 and the change in feet volume (r = -0.23, p = 0.0236. The change in the volume of the feet was negatively related to the change in plasma [Na+] (r = -0.26, p = 0.0227. The change in body mass was negatively related to both post-race plasma [Na+] (r = -0.28, p = 0.0129 and running speed (r = -0.34, p = 0.0028. Conclusions An increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake.

  11. Cubic optical elements for an accommodative intraocular lens.

    Science.gov (United States)

    Simonov, Aleksey N; Vdovin, Gleb; Rombach, Michiel C

    2006-08-21

    We present a new accommodative intraocular lens based on a two-element varifocal Alvarez lens. The intraocular lens consists of (1) an anterior element combining a spherical lens for refractive power with a cubic surface for the varifocal effect, and (2) a posterior element with a cubic surface only. The focal length of the IOL lens changes when the superimposed refractive elements shift in opposite directions in a plane perpendicular to the optical axis. The ciliary muscle will drive the accommodation by a natural process of contraction and relaxation. Results of ray-tracing simulations of the model eye with the two-element intraocular lens are presented for on-axis and off-axis vision. The configuration of the lens is optimized to reduce refractive errors as well as effects of misalignment. A prototype with a clear aperture of ~5.7 mm is manufactured and evaluated in air with a Shack-Hartmann wave-front sensor. It provides an accommodation range of ~4 dioptres in the eye at a ~0.75-mm lateral displacement of the optical elements. The experimentally measured on-axis optical performance of the IOL lens agrees with the theoretically predicted performance.

  12. Nonlinear structure formation in the Cubic Galileon gravity model

    CERN Document Server

    Barreira, Alexandre; Hellwing, Wojciech A; Baugh, Carlton M; Pascoli, Silvia

    2013-01-01

    We model the linear and nonlinear growth of large scale structure in the Cubic Galileon gravity model, by running a suite of N-body cosmological simulations using the {\\tt ECOSMOG} code. Our simulations include the Vainshtein screening effect, which reconciles the Cubic Galileon model with local tests of gravity. In the linear regime, the amplitude of the matter power spectrum increases by $\\sim 25%$ with respect to the standard $\\Lambda$CDM model today. The modified expansion rate accounts for $\\sim 20%$ of this enhancement, while the fifth force is responsible for only $\\sim 5%$. This is because the effective unscreened gravitational strength deviates from standard gravity only at late times, even though it can be twice as large today. In the nonlinear regime ($k \\gtrsim 0.1 h\\rm{Mpc}^{-1}$), the fifth force leads to only a modest increase ($\\lesssim 8%$) in the clustering power on all scales due to the very efficient operation of the Vainshtein mechanism. Such a strong effect is typically not seen in other...

  13. A family of quasi-cubic blended splines and applications

    Institute of Scientific and Technical Information of China (English)

    SU Ben-yue; TAN Jie-qing

    2006-01-01

    A class of quasi-cubic B-spline base functions by trigonometric polynomials are established which inherit properties similar to those of cubic B-spline bases. The corresponding curves with a shape parameter α, defined by the introduced base functions, include the B-spline curves and can approximate the B-spline curves from both sides. The curves can be adjusted easily by using the shape parameter α, where dpi(α,t) is linear with respect to dα for the fixed t. With the shape parameter chosen properly,the defined curves can be used to precisely represent straight line segments, parabola segments, circular arcs and some transcendental curves, and the corresponding tensor product surfaces can also represent spherical surfaces, cylindrical surfaces and some transcendental surfaces exactly. By abandoning positive property, this paper proposes a new C2 continuous blended interpolation spline based on piecewise trigonometric polynomials associated with a sequence of local parameters. Illustration showed that the curves and surfaces constructed by the blended spline can be adjusted easily and freely. The blended interpolation spline curves can be shape-preserving with proper local parameters since these local parameters can be considered to be the magnification ratio to the length of tangent vectors at the interpolating points. The idea is extended to produce blended spline surfaces.

  14. Partially Blended Constrained Rational Cubic Trigonometric Fractal Interpolation Surfaces

    Science.gov (United States)

    Chand, A. K. B.; Tyada, K. R.

    2016-08-01

    Fractal interpolation is an advance technique for visualization of scientific shaped data. In this paper, we present a new family of partially blended rational cubic trigonometric fractal interpolation surfaces (RCTFISs) with a combination of blending functions and univariate rational trigonometric fractal interpolation functions (FIFs) along the grid lines of the interpolation domain. The developed FIFs use rational trigonometric functions pi,j(θ) qi,j(θ), where pi,j(θ) and qi,j(θ) are cubic trigonometric polynomials with four shape parameters. The convergence analysis of partially blended RCTFIS with the original surface data generating function is discussed. We derive sufficient data-dependent conditions on the scaling factors and shape parameters such that the fractal grid line functions lie above the grid lines of a plane Π, and consequently the proposed partially blended RCTFIS lies above the plane Π. Positivity preserving partially blended RCTFIS is a special case of the constrained partially blended RCTFIS. Numerical examples are provided to support the proposed theoretical results.

  15. Observation of Body-Centered Cubic Gold Nanocluster.

    Science.gov (United States)

    Liu, Chao; Li, Tao; Li, Gao; Nobusada, Katsuyuki; Zeng, Chenjie; Pang, Guangsheng; Rosi, Nathaniel L; Jin, Rongchao

    2015-08-17

    The structure of nanoparticles plays a critical role in dictating their material properties. Gold is well known to adopt face-centered cubic (fcc) structure. Herein we report the first observation of a body-centered cubic (bcc) gold nanocluster composed of 38 gold atoms protected by 20 adamantanethiolate ligands and two sulfido atoms ([Au38S2(SR)20], where R=C10H15) as revealed by single-crystal X-ray crystallography. This bcc structure is in striking contrast with the fcc structure of bulk gold and conventional Au nanoparticles, as well as the bi-icosahedral structure of [Au38(SCH2CH2Ph)24]. The bcc nanocluster has a distinct HOMO-LUMO gap of ca. 1.5 eV, much larger than the gap (0.9 eV) of the bi-icosahedral [Au38(SCH2CH2Ph)24]. The unique structure of the bcc gold nanocluster may be promising in catalytic applications.

  16. Four-dimensional black holes in Einsteinian cubic gravity

    Science.gov (United States)

    Bueno, Pablo; Cano, Pablo A.

    2016-12-01

    We construct static and spherically symmetric generalizations of the Schwarzschild- and Reissner-Nordström-(anti-)de Sitter [RN-(A)dS] black-hole solutions in four-dimensional Einsteinian cubic gravity (ECG). The solutions are characterized by a single function which satisfies a nonlinear second-order differential equation. Interestingly, we are able to compute independently the Hawking temperature T , the Wald entropy S and the Abbott-Deser mass M of the solutions analytically as functions of the horizon radius and the ECG coupling constant λ . Using these we show that the first law of black-hole mechanics is exactly satisfied. Some of the solutions have positive specific heat, which makes them thermodynamically stable, even in the uncharged and asymptotically flat case. Further, we claim that, up to cubic order in curvature, ECG is the most general four-dimensional theory of gravity which allows for nontrivial generalizations of Schwarzschild- and RN-(A)dS characterized by a single function which reduce to the usual Einstein gravity solutions when the corresponding higher-order couplings are set to zero.

  17. Novel Cubic Magnetite Nanoparticle Synthesis Using Room Temperature Ionic Liquid

    Directory of Open Access Journals (Sweden)

    M. Sundrarajan

    2012-01-01

    Full Text Available Room Temperature Ionic liquids are relatively more useful in the synthesis of inorganic nanostructured materials because of their unique properties. To synthesize the iron oxide nanoparticle in simple precipitation method, a novel ionic liquid was used as the greener medium and stabilizing agent namely “1-n-butyl-3-methylimidazolium trifluoromethane sulfonate [BMIM][TfO]”. The crystallinity, chemical structure, morphology and magnetic properties of the synthesized magnetite nanoparticles have been characterized by using X-ray diffraction (XRD, Fourier Transform Infrared (FT-IR, Scanning electron microscopy (SEM, Atomic force microscopy(AFM, Transmission electron microscopy (TEM and Vibrating sample magnetometer (VSM studies. The XRD study is divulge that the synthesized magnetite nanoparticles have inverse spinel face centered cubic structure. The FT-IR vibration peaks show the formation of Fe3O4 nanoparticles, where the vibration peak for Fe-O is deliberately presence at 584 cm-1. The average particle size of the synthesized nanoparticles is found to be 35 nm. Homogeneously dispersed cubic shape with superstructure is found through SEM, AFM and TEM examination studies. The synthesized iron oxide nanoparticles have a high saturation magnetization value of 25 emu/g, which is very much useful for biomedical applications.

  18. 40 CFR 201.24 - Procedures for measurement at a 30 meter (100 feet) distance of the noise from locomotive and...

    Science.gov (United States)

    2010-07-01

    ... meter (100 feet) distance of the noise from locomotive and rail car operations and locomotive load cell... Measurement Criteria § 201.24 Procedures for measurement at a 30 meter (100 feet) distance of the noise from... locomotives have passed a distance 152.4 meters (500 feet) or 10 rail cars beyond the point at...

  19. 'Focus on feet'--the effects of systemic lupus erythematosus: a narrative review of the literature.

    Science.gov (United States)

    Williams, A E; Crofts, G; Teh, L S

    2013-09-01

    The manifestations of systemic lupus erythematosus (SLE) vary between individuals, from the severe and life-threatening renal and central nervous system involvement, to the involvement of skin, musculoskeletal and vascular system, and the complications of infection influencing the quality of life. However, as specific manifestations affecting the lower limb are perceived as receiving little focus, the purpose of this narrative literature review is to identify the specific factors associated with SLE that may have implications for lower limb and foot morbidity. A structured search of databases was conducted. The inclusion was restricted to publications in the English language, those that specifically investigate the feet as affected with SLE. No restriction on year of publication was imposed to reduce publication bias and to capture as many publication in relation to feet. Eleven papers fulfilled the inclusion criteria. There were seven additional papers that made observations related to the articular or vascular complications of the feet. This narrative review provides some information on how SLE affects the lower limb and foot in relation to the musculoskeletal and vascular systems. However, there is a lack of literature that specifically focuses on all the manifestations of SLE and the complications associated with its management. There are indications that SLE affects lower limb and foot morbidity but the scale of these problems is unclear and this is partly because of the absence of research and the lack of a 'gold standard' framework for the assessment of the lower limb and foot. In addition to clinical foot health assessment, ultrasonography may be a useful alternative to plain film radiography or magnetic resonance imaging (MRI) in capturing the extent of articular and extra-articular manifestations. Further, the Ankle Brachial Pressure Index (ABPI) may be useful in identifying those with atherosclerosis and ischaemia. There are indications that SLE affects

  20. Design and construction of Thermoelectric Footwear Heating System for illness feet.

    Science.gov (United States)

    Işik, Hakan

    2005-12-01

    In this study, a Thermoelectric Footwear Heating System is developed to use in cold weather conditions. The temperature is controlled by an analog electronic control system. Thermoelectric module is used to heat the bottom of the foot. A negative temperature coefficient (NTC) temperature sensor is used to sense the temperature and the temperature is controlled by an electronic circuit proportionally. A 3.5 V, 5000 mAh rechargeable battery is used as the power source. The temperature range of the system is between +15 degrees C and +50 degrees C. Developed footwear heating system is tested against various temperature conditions, and offer better results in the case of heating the illness feet.

  1. Results of Ponseti Brasil Program: Multicentric Study in 1621 Feet: Preliminary Results.

    Science.gov (United States)

    Nogueira, Monica P; Queiroz, Ana C D B F; Melanda, Alessandro G; Tedesco, Ana P; Brandão, Antonio L G; Beling, Claudio; Violante, Francisco H; Brandão, Gilberto F; Ferreira, Laura F A; Brambila, Leandro S; Leite, Leopoldina M; Zabeu, Jose L; Kim, Jung H; Fernandes, Kalyana E; Arima, Marcia A S; Aguilar, Maria D P Q; Farias Filho, Orlando C D; Oliveira Filho, Oscar B D A; Pinho, Solange D S; Moulin, Paulo; Volpi, Reinaldo; Fox, Mark; Greenwald, Miles F; Lyle, Brandon; Morcuende, Jose A

    The Ponseti method has been shown to be the most effective treatment for congenital clubfoot. The current challenge is to establish sustainable national clubfoot treatment programs that utilize the Ponseti method and integrate it within a nation's governmental health system. The Brazilian Ponseti Program (Programa Ponseti Brasil) has increased awareness of the utility of the Ponseti method and has trained >500 Brazilian orthopaedic surgeons in it. A group of 18 of those surgeons had been able to reproduce the Ponseti clubfoot treatment, and compiled their initial results through structured spreadsheet. The study compiled 1040 patients for a total of 1621 feet. The average follow-up time was 2.3 years with an average correction time of approximately 3 months. Patients required an average of 6.40 casts to achieve correction. This study demonstrates that good initial correction rates are reproducible after training; from 1040 patients only 1.4% required a posteromedial release. Level IV.

  2. Vertical illusory self-motion through haptic stimulation of the feet

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Nilsson, Niels Christian; Turchet, Luca

    2012-01-01

    Circular and linear self-motion illusions induced through visual and auditory stimuli have been studied rather extensively. While the ability of haptic stimuli to augment such illusions has been investigated, the self-motion illusions which primarily are induced by stimulation of the haptic...... modality remain relatively unexplored. In this paper, we present an experiment performed with the intention of investigating whether it is possible to use haptic stimulation of the main supporting areas of the feet to induce vertical illusory self-motion on behalf of unrestrained participants during...... to generate the haptic feedback while the final condition included no haptic feedback. Analysis of self-reports were used to assess the participants' experience of illusory self-motion. The results indicate that such illusions are indeed possible. Significant differences were found between the condition...

  3. SPECTRO-POLARIMETRIC IMAGING REVEALS HELICAL MAGNETIC FIELDS IN SOLAR PROMINENCE FEET

    Energy Technology Data Exchange (ETDEWEB)

    González, M. J. Martínez; Sainz, R. Manso; Ramos, A. Asensio; Beck, C.; Díaz, A. J. [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Rodríguez, J. de la Cruz [Institute for Solar Physics, Department of Astronomy, Stockholm University, Albanova University Center, SE-10691 Stockholm (Sweden)

    2015-03-20

    Solar prominences are clouds of cool plasma levitating above the solar surface and insulated from the million-degree corona by magnetic fields. They form in regions of complex magnetic topology, characterized by non-potential fields, which can evolve abruptly, disintegrating the prominence and ejecting magnetized material into the heliosphere. However, their physics is not yet fully understood because mapping such complex magnetic configurations and their evolution is extremely challenging, and must often be guessed by proxy from photometric observations. Using state-of-the-art spectro-polarimetric data, we reconstruct the structure of the magnetic field in a prominence. We find that prominence feet harbor helical magnetic fields connecting the prominence to the solar surface below.

  4. Healing of ulcers on the feet correlated with distal blood pressure measurements in occlusive arterial disease

    DEFF Research Database (Denmark)

    Holstein, P; Lassen, N A

    1980-01-01

    The frequency of healing in subchronic ulcers in 66 feet in 62 patients with arterial occlusive disease was correlated with the systolic digital blood pressure (SDBP) and the systolic ankle blood pressure (SABP), both measured with a strain gauge, and with the skin perfusion pressure on the heel...... of healing correlated significantly with the three distal blood pressure parameters investigated, the closest correlation being with the SDBP measured at the final examination, i.e. just after healing of the ulcer or just before an inevitable major amputation. Of the 22 cases with SDBP below 20 mmHg only two...... and peripheral neuropathy were frequent in the diabetic group. The data show that the systolic digital blood pressure is a particularly valuable prognostic parameter....

  5. Three cases of feet and hand amputation from Medieval Estremoz, Portugal.

    Science.gov (United States)

    Fernandes, Teresa; Liberato, Marco; Marques, Carina; Cunha, Eugénia

    2017-09-01

    Peri-mortem limb amputations are rarely reported in the paleopathological literature. The cases reported here concern severing of both hands and feet observed in three adult male skeletons, exhumed from the medieval Portuguese necropolis of Rossio do Marquês de Pombal, Estremoz, Portugal. The fact that they were found in the same site, in graves placed side by side, that all are young males, and that the three skeletons show similar perimortem injuries, make this a unique case meriting detailed analysis. Considering the lesions' location and pattern, as well as historical data, we hypothesize that this is a case of amputation as a consequence of judicial punishment. Estremoz was an important city in sustaining the Royal power at a regional scale during the medieval period. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Key parameters governing the densification of cubic-Li7La3Zr2O12 Li+ conductors

    Science.gov (United States)

    Yi, Eongyu; Wang, Weimin; Kieffer, John; Laine, Richard M.

    2017-06-01

    Cubic-Li7La3Zr2O12 (LLZO) is regarded as one of the most promising solid electrolytes for the construction of inherently safe, next generation all-solid-state Li batteries. Unfortunately, sintering these materials to full density with controlled grain sizes, mechanical and electrochemical properties relies on energy and equipment intensive processes. In this work, we elucidate key parameters dictating LLZO densification by tracing the compositional and structural changes during processing calcined and ball-milled Al3+ doped LLZO powders. We find that the powders undergo ion (Li+/H+) exchange during room temperature processing, such that on heating, the protonated LLZO lattice collapses and crystallizes to its constituent oxides, leading to reaction driven densification at sizes and protonation cannot be decoupled, and actually aid densification. We conclude that using fully decomposed nanoparticle mixtures, as obtained by liquid-feed flame spray pyrolysis, provides an ideal approach to use high surface and reaction energy to drive densification, resulting in pressureless sintering of Ga3+ doped LLZO thin films (25 μm) at 1130 °C/0.3 h to ideal microstructures (95 ± 1% density, 1.2 ± 0.2 μm average grain size) normally accessible only by pressure-assisted sintering. Such films offer both high ionic conductivity (1.3 ± 0.1 mS cm-1) and record low ionic area specific resistance (2 Ω cm2).

  7. Are old running shoes detrimental to your feet? A pedobarographic study

    Directory of Open Access Journals (Sweden)

    Makwana Nilesh

    2011-08-01

    Full Text Available Abstract Background Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes. Findings This was a prospective study involving 11 healthy female volunteers with no previous foot and ankle problems. New running shoes were provided to the participants. Plantar pressures were measured using the Novel Pedar system while walking with new and participants' personal old running shoes. Plantar pressures were measured in nine areas of the feet. Demographic data, age of old running shoes, Body Mass Index (BMI, peak pressures and pressure-time integral were acquired. The right and left feet were selected at random and assessed separately. Statistical analysis was done using the paired t test to compare measurements between old and new running shoes. The mean peak pressures were higher in new running shoes (330.5 ± 79.6 kiloPascals kPa when compared to used old running shoes (304 ± 58.1 kPa (p = 0.01. The pressure-time integral was significantly higher in the new running shoes (110 ± 28.3 kPa s compared to used old running shoes (100.7 ± 24.0 kPa s (p = 0.01. Conclusion Plantar pressure measurements in general were higher in new running shoes. This could be due to the lack of flexibility in new running shoes. The risk of injury to the foot and ankle would appear to be higher if running shoes are changed frequently. We recommend breaking into new running shoes slowly using them for mild physical activity.

  8. Antiwrinkle effect of topical adhesive pads on crow's feet: How long does the effect last for?

    Science.gov (United States)

    Mazzarello, Vittorio; Ferrari, Marco; Bulla, Antonio; Piu, Gabriella; Montella, Andrea

    2017-08-28

    Adhesive pads should reduce the action of the local muscle contraction on the skin leading to a decrease in the depth of existing wrinkles and the formation of new dynamic wrinkles. This study aims at assessing the antiwrinkles action of adhesive pads during time, and the temporary improvement of facial skin appearance by reducing the vision of linear wrinkles and improving skin elasticity. Thirty-nine subjects participated to a placebo-controlled study. In the short-term test, the measurements were taken 15, 30, and 60 minutes following 30 minutes application of the product; in the long-term test, the measurements were taken after wearing pads every night for 4 weeks. The roughness parameter of the skin surface was calculated by using a profilometry software 3D MEX(®) . In the short- and long-term tests, analyzing the average of the elastomeric measurements, no significant change was observed in any of the parameters analyzed after 15, 30, and 60 minutes. The adhesive pad decreased significantly all roughness skin parameters 15 minutes after short-term application and until 60 minutes after long-term application. These changes did not occur in the contralateral untreated zone. The use of topical adhesive pads improves wrinkles in the crow's feet area in the first hour after use. However, patient self-evaluation indicated that the use of topical adhesive pads for 3 weeks may offer subjective improvement in crow's feet zone over a 2 hour period. Topical adhesive pads are safe to use and tolerable for most users. © 2017 Wiley Periodicals, Inc.

  9. The initial ultrasonographic examination of hands and feet joints in patients with early rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Monika Ponikowska

    2015-09-01

    Full Text Available Objectives : The aim was to assess of the morphology, intensity, and activity of changes in the first ultrasonographic (US examination of hands and feet in patients with early arthritis (lasting up to 12 months who were ultimately diagnosed with rheumatoid arthritis (RA. An attempt was made to demonstrate a correlation between the intensity of lesions in US and selected laboratory parameters. Material and methods : Ultrasonographic examination was performed using a LOGIC GE 500 device on a group of 60 patients with arthritis (46 women, 14 men aged 18–80, previously untreated. In total, 3120 hand and feet joints were examined. The assessment focused on the presence of joint effusion, synovial proliferation and power Doppler signals (assessed on a semi-quantitative scale. Each patient underwent laboratory tests, necessary for making a diagnosis. In order to analyze the correlations between changes in US and laboratory parameters, erythrocyte sedimentation rate (ESR, reactive protein test (CRP, rheumatoid factor (RF, and anti-citrullinated protein antibodies (ACPAs were used. Results : In the study group, the average duration of arthritis symptoms until the first US examination was 5.6 months. Among the 3120 examined hand and foot joints, deviations from the norm appeared in 1093 joints, synovial hypertrophy was found in 471 joints (grade 1 synovial hypertrophy was reported most frequently, while presence of signal in Power Doppler was revealed in 261 joints (grade 1 was observed most frequently. A statistically significant correlation was found between the intensity of changes in Power Doppler and CRP concentration. Conclusions : In patients with increased concentrations of CRP, we may expect arthritis of higher intensity, therefore, in order to prevent the progression of destructive changes, it is necessary to quickly implement effective disease-modifying antirheumatic treatment. The conducted research showed that the activity of joint

  10. Energy storage and release of prosthetic feet. Part 1: Biomechanical analysis related to user benefits.

    Science.gov (United States)

    Postema, K; Hermens, H J; de Vries, J; Koopman, H F; Eisma, W H

    1997-04-01

    The energy storing and releasing behaviour of 2 energy storing feet (ESF) and 2 conventional prosthetic feet (CF) were compared (ESF: Otto Bock Dynamic Pro and Hanger Quantum; CF: Otto Bock Multi Axial and Otto Bock Lager). Ten trans-tibial amputees were selected. The study was designed as a double-blind, randomised trial. For gait analysis a VICON motion analysis system was used with 2 AMTI force platforms. A special measuring device was used for measuring energy storage and release of the foot during a simulated step. The impulses of the anteroposterior component of the ground force showed small, statistically non-significant differences (deceleration phase: 22.7-23.4 Ns; acceleration phase: 17.0-18.4 Ns). The power storage and release phases as well as the net results also showed small differences (maximum difference in net result is 0.03 J kg-1). It was estimated that these differences lead to a maximum saving of 3% of metabolic energy during walking. It was considered unlikely that the subjects would notice this difference. It was concluded that during walking differences in mechanical energy expenditure of this magnitude are probably not of clinical relevance. Ankle power, as an indicator for energy storage and release gave different results to the energy storage and release as measured with the special test device, especially during landing response. In the biomechanical model (based on inverse dynamics) used in the gait analysis the deformation of the material is not taken into consideration and hence this method of gait analysis is probably not suitable for calculation of shock absorption.

  11. Non-spherical micelles in an oil-in-water cubic phase

    DEFF Research Database (Denmark)

    Leaver, M.; Rajagopalan, V.; Ulf, O.

    2000-01-01

    The cubic phase formed between the microemulsion and hexagonal phases of the ternary pentaethylene glycol dodecyl ether (C12E5)-decane-water system and that doped with small amounts of sodium dodecylsulfate (SDS) have been investigated. The presence of discrete oil-swollen micelles in the cubic...... phase, both with and without SDS, was established by NMR self-diffusion. In addition H-2 NMR relaxation experiments have demonstrated that the micelles in the cubic phase are non-spherical, having grown and changed shape upon formation of the cubic phase from the micellar solution. Small angle...... scattering experiments indicate that the lattice parameter for the cubic phase is inconsistent with a simple packing of micelles. Whilst insufficient reflections were observed to establish the space group of the cubic phase uniquely, those that were are consistent with two commonly observed space groups...

  12. Analytical Approximate Solutions for the Cubic-Quintic Duffing Oscillator in Terms of Elementary Functions

    OpenAIRE

    A. Beléndez; ALVAREZ, M. L.; Francés, J.; S. Bleda; Beléndez, T.; Nájera, A.; Arribas, E.

    2012-01-01

    Accurate approximate closed-form solutions for the cubic-quintic Duffing oscillator are obtained in terms of elementary functions. To do this, we use the previous results obtained using a cubication method in which the restoring force is expanded in Chebyshev polynomials and the original nonlinear differential equation is approximated by a cubic Duffing equation. Explicit approximate solutions are then expressed as a function of the complete elliptic integral of the first kind and the Jacobi ...

  13. Quantum-Carnot engine for particle confined to cubic potential

    Science.gov (United States)

    Sutantyo, Trengginas Eka P.; Belfaqih, Idrus H.; Prayitno, T. B.

    2015-09-01

    Carnot cycle consists of isothermal and adiabatic processes which are reversible. Using analogy in quantum mechanics, these processes can be well explained by replacing variables in classical process with a quantum system. Quantum system which is shown in this paper is a particle that moves under the influence of a cubic potential which is restricted only to the state of the two energy levels. At the end, the efficiency of the system is shown as a function of the width ratio between the initial conditions and the farthest wall while expanding. Furthermore, the system efficiency will be considered 1D and 2D cases. The providing efficiencies are different due to the influence of the degeneration of energy and the degrees of freedom of the system.

  14. Gauge Fixing of Modified Cubic Open Superstring Field Theory

    CERN Document Server

    Kohriki, Maiko; Kunitomo, Hiroshi

    2011-01-01

    The gauge-fixing problem of modified cubic open superstring field theory is discussed in detail both for the Ramond and Neveu-Schwarz sectors in the Batalin-Vilkovisky (BV) framework. We prove for the first time that the same form of action as the classical gauge-invariant one with the ghost-number constraint on the string field relaxed gives the master action satisfying the BV master equation. This is achieved by identifying independent component fields based on the analysis of the kernel structure of the inverse picture changing operator. The explicit gauge-fixing conditions for the component fields are discussed. In a kind of $b_0=0$ gauge, we explicitly obtain the NS propagator which has poles at the zeros of the Virasoro operator $L_0$.

  15. Quantum-Carnot engine for particle confined to cubic potential

    Energy Technology Data Exchange (ETDEWEB)

    Sutantyo, Trengginas Eka P., E-mail: trengginas.eka@gmail.com; Belfaqih, Idrus H., E-mail: idrushusin21@gmail.com; Prayitno, T. B., E-mail: teguh-budi@unj.ac.id [Department of Physics, State University of Jakarta, Jl. Pemuda No.10, Rawamangun, Jakarta Timur 13220 (Indonesia)

    2015-09-30

    Carnot cycle consists of isothermal and adiabatic processes which are reversible. Using analogy in quantum mechanics, these processes can be well explained by replacing variables in classical process with a quantum system. Quantum system which is shown in this paper is a particle that moves under the influence of a cubic potential which is restricted only to the state of the two energy levels. At the end, the efficiency of the system is shown as a function of the width ratio between the initial conditions and the farthest wall while expanding. Furthermore, the system efficiency will be considered 1D and 2D cases. The providing efficiencies are different due to the influence of the degeneration of energy and the degrees of freedom of the system.

  16. Perbaikan Metode Penghitungan Debit Sungai Menggunakan Cubic Spline Interpolation

    Directory of Open Access Journals (Sweden)

    Budi I. Setiawan

    2007-09-01

    Full Text Available Makalah ini menyajikan perbaikan metode pengukuran debit sungai menggunakan fungsi cubic spline interpolation. Fungi ini digunakan untuk menggambarkan profil sungai secara kontinyu yang terbentuk atas hasil pengukuran jarak dan kedalaman sungai. Dengan metoda baru ini, luas dan perimeter sungai lebih mudah, cepat dan tepat dihitung. Demikian pula, fungsi kebalikannnya (inverse function tersedia menggunakan metode. Newton-Raphson sehingga memudahkan dalam perhitungan luas dan perimeter bila tinggi air sungai diketahui. Metode baru ini dapat langsung menghitung debit sungaimenggunakan formula Manning, dan menghasilkan kurva debit (rating curve. Dalam makalah ini dikemukaan satu canton pengukuran debit sungai Rudeng Aceh. Sungai ini mempunyai lebar sekitar 120 m dan kedalaman 7 m, dan pada saat pengukuran mempunyai debit 41 .3 m3/s, serta kurva debitnya mengikuti formula: Q= 0.1649 x H 2.884 , dimana Q debit (m3/s dan H tinggi air dari dasar sungai (m.

  17. On the undamped vibration absorber with cubic stiffness characteristics

    Science.gov (United States)

    Gatti, G.

    2016-09-01

    In order to improve the performance of a vibration absorber, a nonlinear spring can be used on purpose. This paper presents an analytical insight on the characteristics of an undamped nonlinear vibration absorber when it is attached to a linear spring-mass-damper oscillator. In particular, the nonlinear attachment is modelled as a Duffing's oscillator with a spring characteristics having a linear positive stiffness term plus a cubic stiffness term. The effects of the nonlinearity, mass ratio and frequency ratio are investigated based on an approximate analytical formulation of the amplitude-frequency equation. Comparisons to the linear case are shown in terms of the frequency response curves. The nonlinear absorber seems to show an improved robustness to mistuning respect to the corresponding linear device. However, such a better robustness may be limited by some instability of the expected harmonic response.

  18. Cubic Spline Interpolation Reveals Different Evolutionary Trends of Various Species

    Directory of Open Access Journals (Sweden)

    Li Zhiqiang

    2016-01-01

    Full Text Available Instead of being uniform in each branch of the biological evolutionary tree, the speed of evolution, measured in the number of mutations over a fixed number of years, seems to be much faster or much slower than average in some branches of the evolutionary tree. This paper describes an evolutionary trend discovery algorithm that uses cubic spline interpolation for various branches of the evolutionary tree. As shown in an example, within the vertebrate evolutionary tree, human evolution seems to be currently speeding up while the evolution of chickens is slowing down. The new algorithm can automatically identify those branches and times when something unusual has taken place, aiding data analytics of evolutionary data.

  19. Palladium in cubic silicon carbide: Stability and kinetics

    Science.gov (United States)

    Roma, Guido

    2009-12-01

    Several technological applications of silicon carbide are concerned with the introduction of palladium impurities. Be it intentional or not, this may lead to the formation of silicides. Not only this process is not well understood, but the basic properties of palladium impurities in silicon carbide, such as solubility or diffusion mechanisms, are far from being known. Here the stability and kinetics of isolated Pd impurities in cubic silicon carbide are studied by first principles calculations in the framework of density functional theory. The preferential insertion sites, as well as the main migration mechanisms, are analyzed and presented here, together with the results for solution and migration energies. The early stages of nucleation are discussed based on the properties of isolated impurities and the smallest clusters.

  20. Four-dimensional black holes in Einsteinian cubic gravity

    CERN Document Server

    Bueno, Pablo

    2016-01-01

    We construct static and spherically symmetric generalizations of the Schwarzschild- and Reissner-Nordstr\\"om-(Anti) de Sitter (RN-(A)dS) black-hole solutions in four-dimensional Einsteinian cubic gravity (ECG). The solutions are determined by a single blackening factor which satisfies a non-linear second-order differential equation. Interestingly, we are able to compute independently the Hawking temperature $T$, the Wald entropy $\\mathsf{S}$ and the Abbott-Deser mass $M$ of the solutions analytically as functions of the horizon radius and the ECG coupling constant $\\lambda$. Using these we show that the first law of black-hole mechanics is exactly satisfied. Some of the solutions have positive specific heat, which makes them thermodynamically stable, even in the uncharged and asymptotically flat case.

  1. Structure and energetics of nanotwins in cubic boron nitrides

    Science.gov (United States)

    Zheng, Shijian; Zhang, Ruifeng; Huang, Rong; Taniguchi, Takashi; Ma, Xiuliang; Ikuhara, Yuichi; Beyerlein, Irene J.

    2016-08-01

    Recently, nanotwinned cubic boron nitrides (NT c-BN) have demonstrated extraordinary leaps in hardness. However, an understanding of the underlying mechanisms that enable nanotwins to give orders of magnitude increases in material hardness is still lacking. Here, using transmission electron microscopy, we report that the defect density of twin boundaries depends on nanotwin thickness, becoming defect-free, and hence more stable, as it decreases below 5 nm. Using ab initio density functional theory calculations, we reveal that the Shockley partials, which may dominate plastic deformation in c-BNs, show a high energetic barrier. We also report that the c-BN twin boundary has an asymmetrically charged electronic structure that would resist migration of the twin boundary under stress. These results provide important insight into possible nanotwin hardening mechanisms in c-BN, as well as how to design these nanostructured materials to reach their full potential in hardness and strength.

  2. Linear and cubic dynamic susceptibilities in quantum spin glass

    CERN Document Server

    Busiello, G; Sushkova, V G

    2001-01-01

    The low temperature behaviour of the dynamic nonlinear (cubic) susceptibility chi sub 3 sup ' (omega, T) in quantum d-dimensional Ising spin glass with short-range interactions between spins is investigated in terms of the quantum droplet model and the quantum-mechanical nonlinear response theory is employed. We have revealed a glassy like behaviour of droplet dynamics. The frequency dependence of chi sub 3 sup ' (omega, T) is very remarkable, the temperature dependence is found at very low temperatures (quantum regime). The nonlinear response depends on the tunneling rate for a droplet which regulates the strength of quantum fluctuations. This response has a strong dependence on the distribution of droplet free energies and on the droplet length scale average. Implications for experiments in quantum spin glasses like disordered dipolar quantum Ising magnet LiHo sub x Y sub 1 sub - sub x F sub 4 and pseudospin are noted.

  3. A cubic autocatalytic reaction in a continuous stirred tank reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yakubu, Aisha Aliyu; Yatim, Yazariah Mohd [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang Malaysia (Malaysia)

    2015-10-22

    In the present study, the dynamics of the cubic autocatalytic reaction model in a continuous stirred tank reactor with linear autocatalyst decay is studied. This model describes the behavior of two chemicals (reactant and autocatalyst) flowing into the tank reactor. The behavior of the model is studied analytically and numerically. The steady state solutions are obtained for two cases, i.e. with the presence of an autocatalyst and its absence in the inflow. In the case with an autocatalyst, the model has a stable steady state. While in the case without an autocatalyst, the model exhibits three steady states, where one of the steady state is stable, the second is a saddle point while the last is spiral node. The last steady state losses stability through Hopf bifurcation and the location is determined. The physical interpretations of the results are also presented.

  4. Submicron cubic boron nitride as hard as diamond

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guoduan; Kou, Zili, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Wang, Yonghua [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Yan, Xiaozhi, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Li, Wentao [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203 (China); Bi, Yan [Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China); Leng, Yang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong (China); He, Duanwei [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-03-23

    Here, we report the sintering of aggregated submicron cubic boron nitride (sm-cBN) at a pressure of 8 GPa. The sintered cBN compacts exhibit hardness values comparable to that of single crystal diamond, fracture toughness about 5-fold that of cBN single crystal, in combination with a high oxidization temperature. Thus, another way has been demonstrated to improve the mechanical properties of cBN besides reducing the grain size to nano scale. In contrast to other ultrahard compacts with similar hardness, the sm-cBN aggregates are better placed for potential industrial application, as their relative low pressure manufacturing perhaps be easier and cheaper.

  5. PT-Symmetric Cubic Anharmonic Oscillator as a Physical Model

    CERN Document Server

    Mostafazadeh, A

    2004-01-01

    We perform a perturbative calculation of the physical observables, in particular pseudo-Hermitian position and momentum operators, the equivalent Hermitian Hamiltonian operator, and the classical Hamiltonian for the PT-symmetric cubic anharmonic oscillator, $ H=p^1/(2m)+\\mu^2x^2/2+i\\epsilon x^3 $. Ignoring terms of order $ \\epsilon^4 $ and higher, we show that this system describes an ordinary quartic anharmonic oscillator with a position-dependent mass and real and positive coupling constants. This observation elucidates the classical origin of the reality and positivity of the energy spectrum. We also discuss the quantum-classical correspondence for this PT-symmetric system, compute the associated conserved probability density, and comment on the issue of factor-ordering in the pseudo-Hermitian canonical quantization of the underlying classical system.

  6. Enhanced initial protein adsorption on an engineered nanostructured cubic zirconia

    CERN Document Server

    Sabirianov, R F; Namavar, F

    2010-01-01

    Motivated by experimentally observed biocompatibility enhancement of nanoengineered cubic zirconia ZrO2 coatings to mesenchymal stromal cells, we have carried out computational analysis of the initial immobilization of one of known structural fragment of the adhesive protein (fibronectin) on the corresponding surface. We constructed an atomistic model of the zirconia nano-hillock of 3-fold symmetry based on AFM and TEM images. First-principle quantum-mechanical calculations show a substantial variation of electrostatic potential at the hillock due to the presence of surface features such as edges and vertexes. Using an implemented Monte Carlo simulated annealing method we found the orientation of the immobilized protein on the zirconia surface (both flat and nanostructured) and contribution of the each amino acid residue from the protein sequence to the adsorption energy. Accounting for the variation of the dielectric permittivity at the protein-implant interface we use a model distance-dependent dielectric f...

  7. Inverse cubic law of index fluctuation distribution in Indian markets

    CERN Document Server

    Pan, R K; Pan, Raj Kumar; Sinha, Sitabhra

    2006-01-01

    One of the principal statistical features characterizing the activity in financial markets is the distribution of fluctuations in market indicators such as the index. While the developed stock markets such as the New York Stock Exchange (NYSE) have been found to show heavy-tailed fluctuation distribution, there have been claims that emerging markets behave differently. Here we investigate the distribution of several indices from the Indian financial market, one of the largest emerging markets in the world. We have used both tick-by-tick data from the National Stock Exchange (NSE) and daily closing data from both NSE and Bombay Stock Exchange (BSE). We find that the cumulative distribution of index fluctuations has long tails consistent with a power law having exponent $\\alpha \\approx 3$, independent of the time-scale of observation or the market index used for the analysis. This ``inverse cubic law'' is quantitatively similar to what has been observed in developed markets, thereby providing strong evidence th...

  8. Entanglement across a cubic interface in 3+1 dimensions

    Science.gov (United States)

    Devakul, Trithep; Singh, Rajiv R. P.

    2014-08-01

    We calculate the area, edge, and corner Renyi entanglement entropies in the ground state of the transverse-field Ising model, on a simple-cubic lattice, by high-field and low-field series expansions. We find that while the area term is positive and the line term is negative as required by strong subadditivity, the corner contributions are positive in three dimensions. Analysis of the series suggests that the expansions converge up to the physical critical point from both sides. The leading area-law Renyi entropies match nicely from the high- and low-field expansions at the critical point, forming a sharp cusp there. We calculate the coefficients of the logarithmic divergence associated with the corner entropy and compare them with conformal field theory results with smooth interfaces and find a striking correspondence.

  9. Energy Density Bounds in Cubic Quasi-Topological Cosmology

    CERN Document Server

    dS, U Camara; Sotkov, G M

    2013-01-01

    We investigate the thermodynamical and causal consistency of cosmological models of the cubic Quasi-Topological Gravity (QTG) in four dimensions, as well as their phenomenological consequences. Specific restrictions on the maximal values of the matter densities are derived by requiring the apparent horizon's entropy to be a non-negative, non-decreasing function of time. The QTG counterpart of the Einstein-Hilbert (EH) gravity model of linear equation of state is studied in detail. An important feature of this particular QTG cosmological model is the new early-time acceleration period of the evolution of the Universe, together with the standard late-time acceleration present in the original EH model. The QTG correction to the causal diamond's volume is also calculated.

  10. Room temperature quantum emission from cubic silicon carbide nanoparticles.

    Science.gov (United States)

    Castelletto, Stefania; Johnson, Brett C; Zachreson, Cameron; Beke, David; Balogh, István; Ohshima, Takeshi; Aharonovich, Igor; Gali, Adam

    2014-08-26

    The photoluminescence (PL) arising from silicon carbide nanoparticles has so far been associated with the quantum confinement effect or to radiative transitions between electronically active surface states. In this work we show that cubic phase silicon carbide nanoparticles with diameters in the range 45-500 nm can host other point defects responsible for photoinduced intrabandgap PL. We demonstrate that these nanoparticles exhibit single photon emission at room temperature with record saturation count rates of 7 × 10(6) counts/s. The realization of nonclassical emission from SiC nanoparticles extends their potential use from fluorescence biomarker beads to optically active quantum elements for next generation quantum sensing and nanophotonics. The single photon emission is related to single isolated SiC defects that give rise to states within the bandgap.

  11. Spatial 't Hooft loop to cubic order in hot QCD

    CERN Document Server

    Giovannangeli, P

    2002-01-01

    Spatial 't Hooft loops of strength k measure the qualitative change in the behaviour of electric colour flux in confined and deconfined phase of SU (N) gauge theory. They show an area law in the deconfined phase, known analytica lly to two loop order with a ``k-scaling'' law k(N-k). In this paper we comput e the O(g^3) correction to the tension. It is due to neutral gluon fields that get their mass through interaction with the wall. The simple k-scaling is lost in cubic order. The generic problem of non-convexity shows up in this order an d the cure is provided. The result for large N is explicitely given. We show tha t nonperturbative effects appear at O(g^5).

  12. Plasmon polaritons in cubic lattices of spherical metallic nanoparticles

    CERN Document Server

    Lamowski, Simon; Mariani, Eros; Weick, Guillaume; Pauly, Fabian

    2016-01-01

    We investigate theoretically plasmon polaritons in cubic lattices of interacting spherical metallic nanoparticles. Dipolar localized surface plasmons on each nanoparticle couple through the near field dipole-dipole interaction and form collective plasmons which extend over the whole metamaterial. Coupling these collective plasmons in turn to photons leads to plasmon polaritons. We derive within a quantum model general semi-analytical expressions to evaluate both plasmon and plasmon-polariton dispersions that fully account for nonlocal effects in the dielectric function of the metamaterial. Within this model, we discuss the influence of different lattice symmetries and predict related polaritonic gaps within the near-infrared to the visible range of the spectrum that depend on wavevector direction and polarization.

  13. Cubic Derivative Interactions and Asymptotic Dynamics of the Galileon Vacuum

    CERN Document Server

    De Arcia, Roberto; León, Genly; Nucamendi, Ulises; Quiros, Israel

    2015-01-01

    In this paper we apply the tools of the dynamical systems theory in order to uncover the whole asymptotic structure of the vacuum interactions of a galileon model with a cubic derivative interaction term. It is shown that, contrary to what occurs in the presence of background matter, the galileon interactions of vacuum appreciably modify the late-time cosmic dynamics. In particular, a local late-time attractor representing phantom behavior arises which is inevitably associated with a big rip singularity. It seems that the gravitational interactions of the background matter with the galileon screen the effects of the gravitational self-interactions of the galileon, thus erasing any potential modification of the late-time dynamics by the galileon vacuum processes. Unlike other galileon models inspired in the DGP scenario, self-accelerating solutions do not arise in this model.

  14. Quantum corrections for the cubic Galileon in the covariant language

    Science.gov (United States)

    Saltas, Ippocratis D.; Vitagliano, Vincenzo

    2017-05-01

    We present for the first time an explicit exposition of quantum corrections within the cubic Galileon theory including the effect of quantum gravity, in a background- and gauge-invariant manner, employing the field-reparametrisation approach of the covariant effective action at 1-loop. We show that the consideration of gravitational effects in combination with the non-linear derivative structure of the theory reveals new interactions at the perturbative level, which manifest themselves as higher-operators in the associated effective action, which' relevance is controlled by appropriate ratios of the cosmological vacuum and the Galileon mass scale. The significance and concept of the covariant approach in this context is discussed, while all calculations are explicitly presented.

  15. Lipidic cubic phase serial millisecond crystallography using synchrotron radiation

    Directory of Open Access Journals (Sweden)

    Przemyslaw Nogly

    2015-03-01

    Full Text Available Lipidic cubic phases (LCPs have emerged as successful matrixes for the crystallization of membrane proteins. Moreover, the viscous LCP also provides a highly effective delivery medium for serial femtosecond crystallography (SFX at X-ray free-electron lasers (XFELs. Here, the adaptation of this technology to perform serial millisecond crystallography (SMX at more widely available synchrotron microfocus beamlines is described. Compared with conventional microcrystallography, LCP-SMX eliminates the need for difficult handling of individual crystals and allows for data collection at room temperature. The technology is demonstrated by solving a structure of the light-driven proton-pump bacteriorhodopsin (bR at a resolution of 2.4 Å. The room-temperature structure of bR is very similar to previous cryogenic structures but shows small yet distinct differences in the retinal ligand and proton-transfer pathway.

  16. Hairy black holes in cubic quasi-topological gravity

    Science.gov (United States)

    Dykaar, Hannah; Hennigar, Robie A.; Mann, Robert B.

    2017-05-01

    We construct a class of five dimensional black hole solutions to cubic quasi-topological gravity with conformal scalar hair and study their thermodynamics. We find these black holes provide the second example of black hole λ-lines: a line of second order (continuous) phase transitions, akin to the fluid/superfluid transition of 4He. Examples of isolated critical points are found for spherical black holes, marking the first in the literature to date. We also find various novel and interesting phase structures, including an isolated critical point occurring in conjunction with a double reentrant phase transition. The AdS vacua of the theory are studied, finding ghost-free configurations where the scalar field takes on a non-zero constant value, in notable contrast to the five dimensional Lovelock case.

  17. Structure and energetics of nanotwins in cubic boron nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Shijian, E-mail: sjzheng@imr.ac.cn, E-mail: zrf@buaa.edu.cn; Ma, Xiuliang [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, Ruifeng, E-mail: sjzheng@imr.ac.cn, E-mail: zrf@buaa.edu.cn [School of Materials Science and Engineering, and International Research Institute for Multidisciplinary Science, Beihang University, Beijing 100191 (China); Huang, Rong [Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200062 (China); Taniguchi, Takashi [National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Ikuhara, Yuichi [Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587 (Japan); Institute of Engineering Innovation, The University of Tokyo, Tokyo 113-8656 (Japan); Beyerlein, Irene J. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-08-22

    Recently, nanotwinned cubic boron nitrides (NT c-BN) have demonstrated extraordinary leaps in hardness. However, an understanding of the underlying mechanisms that enable nanotwins to give orders of magnitude increases in material hardness is still lacking. Here, using transmission electron microscopy, we report that the defect density of twin boundaries depends on nanotwin thickness, becoming defect-free, and hence more stable, as it decreases below 5 nm. Using ab initio density functional theory calculations, we reveal that the Shockley partials, which may dominate plastic deformation in c-BNs, show a high energetic barrier. We also report that the c-BN twin boundary has an asymmetrically charged electronic structure that would resist migration of the twin boundary under stress. These results provide important insight into possible nanotwin hardening mechanisms in c-BN, as well as how to design these nanostructured materials to reach their full potential in hardness and strength.

  18. THERMODYNAMIC PARAMETERS OF LEAD SULFIDE CRYSTALS IN THE CUBIC PHASE

    Directory of Open Access Journals (Sweden)

    T. O. Parashchuk

    2016-07-01

    Full Text Available Geometric and thermodynamic parameters of cubic PbS crystals were obtained using the computer calculations of the thermodynamic parameters within density functional theory method DFT. Cluster models for the calculation based on the analysis of the crystal and electronic structure. Temperature dependence of energy ΔE and enthalpy ΔH, Gibbs free energy ΔG, heat capacity at constant pressure CP and constant volume CV, entropy ΔS were determined on the basis of ab initio calculations of the crystal structure of molecular clusters. Analytical expressions of temperature dependences of thermodynamic parameters which were approximated with quantum-chemical calculation points have been presented. Experimental results compared with theoretically calculated data.

  19. Adaptive Predistortion Using Cubic Spline Nonlinearity Based Hammerstein Modeling

    Science.gov (United States)

    Wu, Xiaofang; Shi, Jianghong

    In this paper, a new Hammerstein predistorter modeling for power amplifier (PA) linearization is proposed. The key feature of the model is that the cubic splines, instead of conventional high-order polynomials, are utilized as the static nonlinearities due to the fact that the splines are able to represent hard nonlinearities accurately and circumvent the numerical instability problem simultaneously. Furthermore, according to the amplifier's AM/AM and AM/PM characteristics, real-valued cubic spline functions are utilized to compensate the nonlinear distortion of the amplifier and the following finite impulse response (FIR) filters are utilized to eliminate the memory effects of the amplifier. In addition, the identification algorithm of the Hammerstein predistorter is discussed. The predistorter is implemented on the indirect learning architecture, and the separable nonlinear least squares (SNLS) Levenberg-Marquardt algorithm is adopted for the sake that the separation method reduces the dimension of the nonlinear search space and thus greatly simplifies the identification procedure. However, the convergence performance of the iterative SNLS algorithm is sensitive to the initial estimation. Therefore an effective normalization strategy is presented to solve this problem. Simulation experiments were carried out on a single-carrier WCDMA signal. Results show that compared to the conventional polynomial predistorters, the proposed Hammerstein predistorter has a higher linearization performance when the PA is near saturation and has a comparable linearization performance when the PA is mildly nonlinear. Furthermore, the proposed predistorter is numerically more stable in all input back-off cases. The results also demonstrate the validity of the convergence scheme.

  20. Cubic liquid crystalline nanoparticles: optimization and evaluation for ocular delivery of tropicamide.

    Science.gov (United States)

    Verma, Purnima; Ahuja, Munish

    2016-10-01

    The purpose of this study was to investigate the potential of cubic liquid crystalline nanoparticles for ocular delivery of tropicamide. Ultrasound-assisted fragmentation of cubic liquid crystalline bulk phases resulted in cubic liquid crystalline nanoparticles employing Pluronic F127 as dispersant. The effects of process variables such as sonication time, sonication amplitude, sonication depth, and pre-mixing time on particle size and polydispersity index was investigated using central composite design. The morphology of tropicamide-loaded nanoparticles was found to be nearly cubical in shape by transmission electron microscopy observation. Further, small angle X-ray scattering experiment confirmed the presence of D and P phase cubic structures in coexistence. The optimized tropicamide-loaded cubic nanoparticles showed in vitro corneal permeation of tropicamide across isolated porcine cornea comparable to its commercial preparation, Tropicacyl®. Ocular tolerance was evaluated by Hen's egg-chorioallantoic membrane test and histological studies. The results of in vivo mydriatic response study demonstrated a remarkably higher area under mydriatic response curve (AUC0→1440 min) values of cubic nanoparticles over Tropicacyl® indicating better therapeutic value of cubic nanoparticles. Furthermore, tropicamide-loaded cubic nanoparticles exhibited prolonged mydriatic effect on rabbits as compared to commercial conventional aqueous ophthalmic solution.

  1. Photographer : JPL Range : 1,094,666 km (677,000 mi.) This false color picture of Callisto was taken

    Science.gov (United States)

    1979-01-01

    Photographer : JPL Range : 1,094,666 km (677,000 mi.) This false color picture of Callisto was taken by Voyager 2 and is centered on 11 degrees N and 171 degrees W. This rendition uses an ultraviolet image for the blue component. Because the surface displays regional contrast in UV, variations in surface materials are apparent. Notice in particular the dark blue haloes which surround bright craters in the eastern hemisphere. The surface of Callisto is the most heavily cratered of the Galilean satellites and resembles ancient heavily cratered terrains on the moon, Mercury and Mars. The bright areas are ejecta thrown out by relatively young impact craters. A large ringed structure, probably an impact basin, is shown in the upper left part of the picture. The color version of this picture was constructed by compositing black and white images taken through the ultraviolet, clear and orange filters.

  2. Methods for Retrievals of CO2 Mixing Ratios from JPL Laser Absorption Spectrometer Flights During a Summer 2011 Campaign

    Science.gov (United States)

    Menzies, Robert T.; Spiers, Gary D.; Jacob, Joseph C.

    2013-01-01

    The JPL airborne Laser Absorption Spectrometer instrument has been flown several times in the 2007-2011 time frame for the purpose of measuring CO2 mixing ratios in the lower atmosphere. This instrument employs CW laser transmitters and coherent detection receivers in the 2.05- micro m spectral region. The Integrated Path Differential Absorption (IPDA) method is used to retrieve weighted CO2 column mixing ratios. We present key features of the evolving LAS signal processing and data analysis algorithms and the calibration/validation methodology. Results from 2011 flights in various U.S. locations include observed mid-day CO2 drawdown in the Midwest and high spatial resolution plume detection during a leg downwind of the Four Corners power plant in New Mexico.

  3. A Rapid Turn-around, Scalable Big Data Processing Capability for the JPL Airborne Snow Observatory (ASO) Mission

    Science.gov (United States)

    Mattmann, C. A.

    2014-12-01

    The JPL Airborne Snow Observatory (ASO) is an integrated LIDAR and Spectrometer measuring snow depth and rate of snow melt in the Sierra Nevadas, specifically, the Tuolumne River Basin, Sierra Nevada, California above the O'Shaughnessy Dam of the Hetch Hetchy reservoir, and the Uncompahgre Basin, Colorado, amongst other sites. The ASO data was delivered to water resource managers from the California Department of Water Resources in under 24 hours from the time that the Twin Otter aircraft landed in Mammoth Lakes, CA to the time disks were plugged in to the ASO Mobile Compute System (MCS) deployed at the Sierra Nevada Aquatic Research Laboratory (SNARL) near the airport. ASO performed weekly flights and each flight took between 500GB to 1 Terabyte of raw data, which was then processed from level 0 data products all the way to full level 4 maps of Snow Water Equivalent, albedo mosaics, and snow depth from LIDAR. These data were produced by Interactive Data analysis Language (IDL) algorithms which were then unobtrusively and automatically integrated into an Apache OODT and Apache Tika based Big Data processing system. Data movement was both electronic and physical including novel uses of LaCie 1 and 2 TeraByte (TB) data bricks and deployment in rugged terrain. The MCS was controlled remotely from the Jet Propulsion Laboratory, California Institute of Technology (JPL) in Pasadena, California on behalf of the National Aeronautics and Space Administration (NASA). Communication was aided through the use of novel Internet Relay Chat (IRC) command and control mechanisms and through the use of the Notifico open source communication tools. This talk will describe the high powered, and light-weight Big Data processing system that we developed for ASO and its implications more broadly for airborne missions at NASA and throughout the government. The lessons learned from ASO show the potential to have a large impact in the development of Big Data processing systems in the years

  4. Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer. Part 1; Stringer-Feet Imperfections and Assembly

    Science.gov (United States)

    Knight, Norman F., Jr.; Song, Kyongchan; Elliott, Kenny B.; Raju, Ivatury S.; Warren, Jerry E.

    2012-01-01

    Elastic-plastic, large-deflection nonlinear stress analyses are performed for the external hat-shaped stringers (or stiffeners) on the intertank portion of the Space Shuttle s external tank. These stringers are subjected to assembly strains when the stringers are initially installed on an intertank panel. Four different stringer-feet configurations including the baseline flat-feet, the heels-up, the diving-board, and the toes-up configurations are considered. The assembly procedure is analytically simulated for each of these stringer configurations. The location, size, and amplitude of the strain field associated with the stringer assembly are sensitive to the assumed geometry and assembly procedure. The von Mises stress distributions from these simulations indicate that localized plasticity will develop around the first eight fasteners for each stringer-feet configuration examined. However, only the toes-up configuration resulted in high assembly hoop strains.

  5. The effect that energy storage and return feet have on the propulsion of the body: a pilot study.

    Science.gov (United States)

    Crimin, Anthony; McGarry, Anthony; Harris, Elena Jane; Solomonidis, Stephan Emanuel

    2014-09-01

    A variety of energy storage and return prosthetic feet are currently available for use within lower limb prostheses. Designs claim to provide a beneficial energy return during push-off, but the extent to which this occurs remains disputed. Techniques currently used to measure energy storage, dissipation and return within the structure of the prosthetic foot are debatable, with limited evidence to support substantial elastic energy storage and return from existing designs. The aim of this study was to evaluate the performance of energy storage and return foot designs through considering the ankle power during push-off and the effect on body centre of mass propulsion. To achieve this aim, the gait patterns of six trans-tibial prosthetic users wearing different designs of energy storage and return feet were analysed while ascending a ramp. Three examples of energy storage and return feet (suitable for moderate activity) were selected and randomly evaluated: the Blatchford's Epirus, Össur Assure and College Park Tribute feet. The power at the anatomical and mechanical ankle joints was integrated to evaluate the work done over the gait cycle. The direction of the inertial force, and therefore propulsion of the body centre of mass, was used to indicate the effect of the energy return by the energy storage and return feet. Results indicate that although energy storage and return feet may provide energy return, the work done around the prosthetic ankle indicates net power absorption. Therefore, the prosthetic limb is unable to contribute to the body centre of mass propulsion to the same extent as the biological limb.

  6. A Cochrane review of the evidence for non-surgical interventions for flexible pediatric flat feet.

    Science.gov (United States)

    Evans, A M; Rome, K

    2011-03-01

    The pediatric flat foot is a frequent presentation in clinical practice, a common concern to parents and continues to be debated within professional ranks. As an entity, it is confused by varied classifications, the notion of well-intended prevention and unsubstantiated, if common, treatment. The available prevalence estimates are all limited by variable sampling, assessment measures and age groups and hence result in disparate findings (0.6-77.9%). Consistently, flat foot has been found to normally reduce with age. The normal findings of flat foot versus children's age estimates that approximately 45% of preschool children, and 15% of older children (average age 10 years) have flat feet. Few flexible flat feet have been found to be symptomatic. Joint hypermobility and increased weight or obesity may increase flat foot prevalence, independently of age. Most attempts at classification of flat foot morphology include the arch, heel position and foot flexibility. Usual assessment methods are footprint measures, X-rays and visual (scaled) observations. There is no standardized framework from which to evaluate the pediatric flat foot. The pediatric flat foot is often unnecessarily treated, being ill-defined and of uncertain prognosis. Contemporary management of the pediatric flat foot is directed algorithmically within this review, according to pain, age, flexibility; considering gender, weight, and joint hypermobility. When foot orthoses are indicated, inexpensive generic appliances will usually suffice. Customised foot orthoses should be reserved for children with foot pain and arthritis, for unusual morphology, or unresponsive cases. Surgery is rarely indicated for pediatric flat foot (unless rigid) and only at the failure of thorough conservative management. The assessment of the pediatric flatfoot needs to be considered with reference to the epidemiological findings, where there is consensus that pediatric flexible flat foot reduces with age and that most children

  7. High altitude dives from 7000 to 14,200 feet in the Himalayas.

    Science.gov (United States)

    Sahni, T K; John, M J; Dhall, A; Chatterjee, A K

    1991-07-01

    Indian Navy divers carried out no-decompression dives at altitudes of 7000 to 14,200 ft (2134-4328 m) in the Nilgiris and Himalayas from May to July 1988. Seventy-eight dives on air and 22 dives on oxygen were carried out at various altitudes. The final dives were at Lake Pangong Tso (4328 m) in Ladakh, Himalayas, to a maximum of 140 feet of sea water (fsw) [42.6 meters of sea water (msw)] equivalent ocean depth in minimum water temperature of 2 degrees C. Oxygen diving at 14,200 ft (4328 m) was not successful. Aspects considered were altitude adaptation, diminished air pressure diving, hypothermia, and remote area survival. Depths at altitude were converted to depths at sea level and were applied to the Royal Navy air tables. Altitude-related manifestations, hypoxia, hypothermia, suspected oxygen toxicity, and equipment failure were observed. It is concluded that stress is due to effects of altitude and cold on man and equipment, as well as changes in diving procedures when diving at high altitudes. Equivalent air depths when applied to Royal Navy tables could be considered a safe method for diving at altitudes.

  8. System overview and walking dynamics of a passive dynamic walking robot with flat feet

    Directory of Open Access Journals (Sweden)

    Xinyu Liu

    2015-12-01

    Full Text Available The concept of “passive dynamic walking robot” refers to the robot that can walk down a shallow slope stably without any actuation and control which shows a limit cycle during walking. By adding actuation at some joints, the passive dynamic walking robot can walk stably on level ground and exhibit more versatile gaits than fully passive robot, namely, the “limit cycle walker.” In this article, we present the mechanical structures and control system design for a passive dynamic walking robot with series elastic actuators at hip joint and ankle joints. We built a walking model that consisted of an upper body, knee joints, and flat feet and derived its walking dynamics that involve double stance phases in a walking cycle based on virtual power principle. The instant just before impact was chosen as the start of one step to reduce the number of independent state variables. A numerical simulation was implemented by using MATLAB, in which the proposed passive dynamic walking model could walk stably down a shallow slope, which proves that the derived walking dynamics are correct. A physical passive robot prototype was built finally, and the experiment results show that by only simple control scheme the passive dynamic robot could walk stably on level ground.

  9. Children with flat feet have weaker toe grip strength than those having a normal arch

    Science.gov (United States)

    Tashiro, Yuto; Fukumoto, Takahiko; Uritani, Daisuke; Matsumoto, Daisuke; Nishiguchi, Shu; Fukutani, Naoto; Adachi, Daiki; Hotta, Takayuki; Morino, Saori; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Aoyama, Tomoki

    2015-01-01

    [Purpose] This study investigated the relationship between toe grip strength and foot posture in children. [Subjects and Methods] A total of 619 children participated in this study. The foot posture of the participants was measured using a foot printer and toe grip strength was measured using a toe grip dynamometer. Children were classified into 3 groups; flatfoot, normal, and high arch, according to Staheli’s arch index. The differences in demographic data and toe grip strength among each foot posture group were analyzed by analysis of variance. Additionally, toe grip strength differences were analyzed by analysis of covariance, adjusted to body mass index, age, and gender. [Results] The number of participants classified as flatfoot, normal, and high arch were 110 (17.8%), 468 (75.6%), and 41 (6.6%), respectively. The toe grip strength of flatfoot children was significantly lower than in normal children, as shown by both analysis of variance and analysis of covariance. [Conclusion] A significant difference was detected in toe grip strength between the low arch and normal foot groups. Therefore, it is suggested that training to increase toe grip strength during childhood may prevent the formation of flat feet or help in the development of arch. PMID:26696732

  10. Postcolonial Myth in Salman Rushdie’s The Ground Beneath Her Feet

    Directory of Open Access Journals (Sweden)

    Doncu Roxana Elena

    2014-01-01

    Full Text Available Postcolonial writers like Salman Rushdie often write back to the “empire” by appropriating myth and allegory. In The Ground beneath Her Feet, Rushdie rewrites the mythological story of Orpheus and Eurydice, using katabasis (the trope of the descent into Hell to comment both on the situation of the postcolonial writer from a personal perspective and to attempt a redefinition of postcolonial migrant identity-formation. Hell has a symbolic function, pointing both to the external context of globalization and migration (which results in the characters’ disorientation and to an interior space which can be interpreted either as a source of unrepressed energies and creativity (in a Romantic vein or as the space of the abject (in the manner of Julia Kristeva. The article sets out to investigate the complex ways in which the Orphic myth and katabasis are employed to shed light on the psychology of the creative artist and on the reconfiguration of identity that becomes the task of the postcolonial migrant subject. The journey into the underworld functions simultaneously as an allegory of artistic creation and identity reconstruction.

  11. WHY CATS LAND ON THEIR FEET: AND 76 OTHER PHYSICAL PARADOXES AND PUZZLES

    Directory of Open Access Journals (Sweden)

    Pedro Zany Caldeira

    Full Text Available Em Why Cats Land On Their Feet: And 76 Other Physical Paradoxes and Puzzles, Mark Levi, professor de matemática na Pennsylvania State University e autor do livro The Mathematical Mechanic: Using Phisical Reasoning to Solve Problems(publicado pela mesma editora, apresenta 77 paradoxos e enigmas da Física (que de fato correspondem a mais de uma centena de problemas, seguindo uma estrutura simples de exploração de cada um deles: Problema / Questão, (Pista, Resposta e Explicação (por vezes mais de uma. Como o próprio autor afirma, "um bom paradoxo físico é (1 uma surpresa, (2 um enigma e (3 uma lição, tudo embrulhado num pacote divertido. Um paradoxo em muitas ocasiões apresenta um argumento muito convincente que conduz a uma conclusão errada que parece certa, ou a uma conclusão certa que parece errada ou surpreendente" (p. 1. E os paradoxos e enigmas não são apenas divertidos, eles também treinam a intuição, a lógica e o pensamento crítico (seja qual for a área de estudo ou ensino.

  12. Using differential reinforcement to improve equine welfare: shaping appropriate truck loading and feet handling.

    Science.gov (United States)

    Slater, Charlotte; Dymond, Simon

    2011-03-01

    Inappropriate behavior during common handling procedures with horses is often subject to aversive treatment. The present study replicated and extended previous findings using differential reinforcement to shape appropriate equine handling behavior. In Study 1, a multiple baseline across subjects design was used with four horses to determine first the effects of shaping target-touch responses and then successive approximations of full truck loading under continuous and intermittent schedules of reinforcement. Full loading responses were shaped and maintained in all four horses and occurrences of inappropriate behaviors reduced to zero. Generalization of the loading response was also observed to both a novel trainer and trailer. In Study 2, a changing criterion design was used to increase the duration of feet handling with one horse. The horse's responding reached the terminal duration criterion of 1min and showed consistent generalization and one-week maintenance. Overall, the results of both studies support the use of applied equine training systems based on positive reinforcement for increasing appropriate behavior during common handling procedures. 2011 Elsevier B.V. All rights reserved.

  13. Radiographic protocol and normal anatomy of the hind feet in the white rhinoceros (Ceratotherium simum).

    Science.gov (United States)

    Dudley, Robert J; Wood, Simon P; Hutchinson, John R; Weller, Renate

    2015-01-01

    Foot pathology is a common and important health concern in captive rhinoceroses worldwide, but osteopathologies are rarely diagnosed, partly because of a lack of radiographic protocols. Here, we aimed to develop the first radiographic protocol for rhinoceros feet and describe the radiographic anatomy of the white rhinoceros (Ceratotherium simum) hind foot (pes). Computed tomographic images were obtained of nine cadaver pedes from seven different white rhinoceroses and assessed for pathology. A single foot deemed free of pathology was radiographed using a range of different projections and exposures to determine the best protocol. 3D models were produced from the CT images and were displayed with the real radiographs to describe the normal radiographic anatomy of the white rhinoceros pes. An optimal radiographic projection was determined for each bone in the rhinoceros pes focusing on highlighting areas where pathology has been previously described. The projections deemed to be most useful were D60Pr-PlDiO (digit III), D45Pr45M-PlDiLO (digit II), and D40Pr35L-PlDiLO (digit IV). The primary beam was centered 5-7 cm proximal to the cuticle on the digit of interest. Articular surfaces, ridges, grooves, tubercles, processes and fossae were identified. The radiographic protocol we have developed along with the normal radiographic anatomy we have described will allow for more accessible and effective diagnosis of white rhinoceros foot osteopathologies.

  14. A prospective study of Japas′ osteotomy in paralytic pes cavus deformity in adolescent feet

    Directory of Open Access Journals (Sweden)

    Chatterjee Protyush

    2009-01-01

    Full Text Available Background: Pes cavus is a progressive and ugly deformity of the foot. Although initially the deformity is painless, with time, painful callosities develop under metatarsal heads and arthritis supervenes later in feet. Mild deformities can be treated with corrective shoes, or foot exercises. However, in others, operative treatment is imperative. Soft tissue operations are largely unsatisfactory and temporary. Bony operations give permanent correction. We present our series of 18 patients of pes cavus in the adolescent age group, treated by Japas′ V-osteotomy of the tarsus. Materials and Methods: 18 patients of paralytic pes cavus deformity were treated by Japas osteotomy, between March 1995 and 2005, at our institute. The age of the patients ranged from 8.6 to 15 years (mean 11.3; 10 were boys and 8 girls. All cases had unilateral involvement, and all, but one, were post-polio cases. Result: The mean follow-up is 5.4 years. Of the 18 patients, 14 had excellent or good corrections; 4 had poor correction/complications. However, those patients could be salvaged by triple arthordesis or Dwyer′s calcaneal osteotomy. Conclusion: Japas′ osteotomy is a satisfactory option for correction of pes cavus deformity in adolescents. In patients who have rigid hind foot equinus or varus, however, the results are compromised.

  15. Effects of surface characteristics on the plantar shape of feet and subjects' perceived sensations.

    Science.gov (United States)

    Witana, Channa P; Goonetilleke, Ravindra S; Xiong, Shuping; Au, Emily Y L

    2009-03-01

    Orthotics and other types of shoe inserts are primarily designed to reduce injury and improve comfort. The interaction between the plantar surface of the foot and the load-bearing surface contributes to foot and surface deformations and hence to perceived comfort, discomfort or pain. The plantar shapes of 16 participants' feet were captured when standing on three support surfaces that had different cushioning properties in the mid-foot region. Foot shape deformations were quantified using 3D laser scans. A questionnaire was used to evaluate the participant's perceptions of perceived shape and perceived feeling. The results showed that the structure in the mid-foot could change shape, independent of the rear-foot and forefoot regions. Participants were capable of identifying the shape changes with distinct preferences towards certain shapes. The cushioning properties of the mid-foot materials also have a direct influence on perceived feelings. This research has strong implications for the design and material selection of orthotics, insoles and footwear.

  16. The underlying structure of skin wrinkles: a hyperspectral approach to crows feet

    Science.gov (United States)

    Puccetti, G.

    2017-02-01

    Skin wrinkles are visually perceived by consumers but they are also known to possess an underlying structure not apparent at the surface of the skin. This underlying structure can be brought out by polarized hyperspectral imaging. Wrinkle patterns of eye crow's feet are used as example to show a deeper existing pattern and their characterization versus age on a group of volunteers. The skin inhomogeneity changes within each layer of the skin and can be observed in the shorter wavelength region of the spectrum, about 450nm to 500nm which are well suited to image skin surface inhomogeneities within the central and deep epidermis. Imaging in the 550nm range can serve as a larger scale topology reference because of its deeper penetration into the upper dermis. This serves to bring out the underlying wrinkle pattern as imprinted by collagen anisotropies around deep folds but unapparent to the eye yet. The approach has potential applications in evaluating the internal skin patterns non visible to the eye by mapping their spectral dispersion. This method has thus potentials to evaluate the extent of subsurface structures such as acne and other scars and thereby the efficacy of treatments.

  17. Design and Stability Analysis of a 3D Rimless Wheel with Flat Feet and Ankle Springs

    Science.gov (United States)

    Narukawa, Terumasa; Takahashi, Masaki; Yoshida, Kazuo

    A two-dimensional rimless wheel provides a simple model of bipedal walking. The motion of the rimless wheel is stable, and this particular property has clarified the fundamental role of a swing leg in planar bipedal walking that addresses the problem of falling forward. In this paper, a three-dimensional rimless wheel is investigated as a simple model of three-dimensional bipedal walking. The 3D rimless wheel model is useful in understanding the essential dynamics of 3D bipedal locomotion. The model consists of two rimless wheels connected by a link at the center of the wheels, and flat feet connected to the spokes with springs. The first numerical stability studies indicated that the motion of the 3D rimless wheel could be unstable; however, numerical simulations and experimental results showed that for a given slope and physical parameters, including the spring constant at the ankles, a stable motion is obtained. This indicates the usefulness of ankle springs in providing stable bipedal locomotion in three-dimensions.

  18. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Science.gov (United States)

    Jizhuang, Fan; Wei, Zhang; Bowen, Yuan; Gangfeng, Liu

    2017-01-01

    ABSTRACT Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11%) between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58%) fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency. PMID:28302669

  19. Treatment of sandal burns of the feet in children in a moist environment.

    Science.gov (United States)

    Shakirov, Babur M

    2014-05-01

    Burns to children's feet are often due to scalds, from hot tap water, as an infant's skin is thinner and hence more susceptible to a full-thickness injury. In Central Asia, and particularly in Uzbekistan, many episodes of burns take place at homes because of using sandal heaters. In the case of sandal burns of the foot, it usually is not only skin that is injured but also underlying tissues: subcutaneous fat, fasciae, muscles and even bones. Many controlled studies have confirmed that wounds heal more readily in a moist, physiological environment. After performing the toilet of burn wounds of the foot, we applied Dermazin cream on the affected areas and then the foot was placed onto a polyethylene packet of large size and fixed by a bandage. Measurement of wound water evaporation was performed every day post-burn. Surgery was usually performed 15-17 days after burn by applying a perforated skin graft or a 0.2-0.3-mm-thick non-perforated skin graft. The procedures helped to improve the general condition of patients, shortened their stay in hospital and also reduced expenses and lessened joint deformities and contracture deformities.

  20. Electric quadrupole interaction in cubic BCC α-Fe

    Energy Technology Data Exchange (ETDEWEB)

    Błachowski, A.; Komędera, K. [Mössbauer Spectroscopy Division, Institute of Physics, Pedagogical University, ul. Podchorążych 2, PL-30-084 Kraków (Poland); Ruebenbauer, K., E-mail: sfrueben@cyf-kr.edu.pl [Mössbauer Spectroscopy Division, Institute of Physics, Pedagogical University, ul. Podchorążych 2, PL-30-084 Kraków (Poland); Cios, G.; Żukrowski, J. [AGH University of Science and Technology, Academic Center for Materials and Nanotechnology, Av. A. Mickiewicza 30, PL-30-059 Kraków (Poland); Górnicki, R. [RENON, ul. Gliniana 15/15, PL-30-732 Kraków (Poland)

    2016-07-15

    Mössbauer transmission spectra for the 14.41-keV resonant line in {sup 57}Fe have been collected at room temperature by using {sup 57}Co(Rh) commercial source and α-Fe strain-free single crystal as an absorber. The absorber was magnetized to saturation in the absorber plane perpendicular to the γ-ray beam axis applying small external magnetic field. Spectra were collected for various orientations of the magnetizing field, the latter lying close to the [110] crystal plane. A positive electric quadrupole coupling constant was found practically independent on the field orientation. One obtains the following value V{sub zz} = +1.61(4) × 10{sup 19} Vm{sup −2} for the (average) principal component of the electric field gradient (EFG) tensor under assumption that the EFG tensor is axially symmetric and the principal axis is aligned with the magnetic hyperfine field acting on the {sup 57}Fe nucleus. The nuclear spectroscopic electric quadrupole moment for the first excited state of the {sup 57}Fe nucleus was adopted as +0.17 b. Similar measurement was performed at room temperature using as-rolled polycrystalline α-Fe foil of high purity in the zero external field. Corresponding value for the principal component of the EFG was found as V{sub zz} = +1.92(4) × 10{sup 19} Vm{sup −2}. Hence, it seems that the origin of the EFG is primarily due to the local (atomic) electronic wave function distortion caused by the spin–orbit interaction between effective electronic spin S and incompletely quenched electronic angular momentum L. It seems as well that the lowest order term proportional to the product L·λ·S dominates, as no direction dependence of the EFG principal component is seen. The lowest order term is isotropic for a cubic symmetry as one has λ=λ 1 for cubic systems with the symbol 1 denoting unit operator and λ being the coupling parameter. - Highlights: • Precision of MS the same as MAPON • Real scans versus magnetization direction • A challenge

  1. New cubic structure compounds as actinide host phases

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovsky, S V [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation); Yudintsev, S V; Livshits, T S, E-mail: profstef@mtu-net.ru [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetny lane 35, Moscow 119017 (Russian Federation)

    2010-03-15

    Various compounds with fluorite (cubic zirconia) and fluorite-derived (pyrochlore, zirconolite) structures are considered as promising actinide host phases at immobilization of actinide-bearing nuclear wastes. Recently some new cubic compounds - stannate and stannate-zirconate pyrochlores, murataite and related phases, and actinide-bearing garnet structure compounds were proposed as perspective matrices for complex actinide wastes. Zirconate pyrochlore (ideally Gd{sub 2}Zr{sub 2}O{sub 7}) has excellent radiation resistance and high chemical durability but requires high temperatures (at least 1500 deg. C) to be produced by hot-pressing from sol-gel derived precursor. Partial Sn{sup 4+} substitution for Zr{sup 4+} reduces production temperature and the compounds REE{sub 2}ZrSnO{sub 7} may be hot-pressed or cold pressed and sintered at {approx}1400 deg. C. Pyrochlore, A{sub 2}B{sub 2}O{sub 7-x} (two-fold elementary fluorite unit cell), and murataite, A{sub 3}B{sub 6}C{sub 2}O{sub 20-y} (three-fold fluorite unit cell), are end-members of the polysomatic series consisting of the phases whose structures are built from alternating pyrochlore and murataite blocks (nano-sized modules) with seven- (2C/3C/2C), five- (2C/3C), eight- (3C/2C/3C) and three-fold (3C - murataite) fluorite unit cells. Actinide content in this series reduces in the row: 2C (pyrochlore) > 7C > 5C > 8C > 3C (murataite). Due to congruent melting murataite-based ceramics may be produced by melting and the firstly segregated phase at melt crystallization is that with the highest fraction of the pyrochlore modules in its structure. The melts containing up to 10 wt. % AnO{sub 2} (An = Th, U, Np, Pu) or REE/An fraction of HLW form at crystallization zoned grains composed sequentially of the 5C {yields} 8C {yields} 3C phases with the highest actinide concentration in the core and the lowest - in the rim of the grains. Radiation resistance of the 'murataite' is comparable to titanate pyrochlores. One

  2. Characterization, Microstructure, and Dielectric properties of cubic pyrochlore structural ceramics

    KAUST Repository

    Li, Yangyang

    2013-05-01

    The (BMN) bulk materials were sintered at 1050°C, 1100°C, 1150°C, 1200°C by the conventional ceramic process, and their microstructure and dielectric properties were investigated by Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Transmission electron microscopy (TEM) (including the X-ray energy dispersive spectrometry EDS and high resolution transmission electron microscopy HRTEM) and dielectric impedance analyzer. We systematically investigated the structure, dielectric properties and voltage tunable property of the ceramics prepared at different sintering temperatures. The XRD patterns demonstrated that the synthesized BMN solid solutions had cubic phase pyrochlore-type structure when sintered at 1050°C or higher, and the lattice parameter (a) of the unit cell in BMN solid solution was calculated to be about 10.56Å. The vibrational peaks observed in the Raman spectra of BMN solid solutions also confirmed the cubic phase pyrochlore-type structure of the synthesized BMN. According to the Scanning Electron Microscope (SEM) images, the grain size increased with increasing sintering temperature. Additionally, it was shown that the densities of the BMN ceramic tablets vary with sintering temperature. The calculated theoretical density for the BMN ceramic tablets sintered at different temperatures is about 6.7521 . The density of the respective measured tablets is usually amounting more than 91% and 5 approaching a maximum value of 96.5% for sintering temperature of 1150°C. The microstructure was investigated by using Scanning Transmission Electron Microscope (STEM), X-ray diffraction (XRD). Combined with the results obtained from the STEM and XRD, the impact of sintering temperature on the macroscopic and microscopic structure was discussed. The relative dielectric constant ( ) and dielectric loss ( ) of the BMN solid solutions were measured to be 161-200 and (at room temperature and 100Hz-1MHz), respectively. The BMN solid

  3. Extending a Property of Cubic Polynomials to Higher-Degree Polynomials

    Science.gov (United States)

    Miller, David A.; Moseley, James

    2012-01-01

    In this paper, the authors examine a property that holds for all cubic polynomials given two zeros. This property is discovered after reviewing a variety of ways to determine the equation of a cubic polynomial given specific conditions through algebra and calculus. At the end of the article, they will connect the property to a very famous method…

  4. Deformation-induced structural transition in body-centred cubic molybdenum.

    Science.gov (United States)

    Wang, S J; Wang, H; Du, K; Zhang, W; Sui, M L; Mao, S X

    2014-03-07

    Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original -oriented body-centred cubic structure to a -oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into -oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama-Wassermann and Kurdjumov-Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions.

  5. The Normals to a Parabola and the Real Roots of a Cubic

    Science.gov (United States)

    Bains, Majinder S.; Thoo, J. B.

    2007-01-01

    The geometric problem of finding the number of normals to the parabola y = x[squared] through a given point is equivalent to the algebraic problem of finding the number of distinct real roots of a cubic equation. Apollonius solved the former problem, and Cardano gave a solution to the latter. The two problems are bridged by Neil's (semi-cubical)…

  6. Deformation-induced structural transition in body-centred cubic molybdenum

    Science.gov (United States)

    Wang, S. J.; Wang, H.; Du, K.; Zhang, W.; Sui, M. L.; Mao, S. X.

    2014-03-01

    Molybdenum is a refractory metal that is stable in a body-centred cubic structure at all temperatures before melting. Plastic deformation via structural transitions has never been reported for pure molybdenum, while transformation coupled with plasticity is well known for many alloys and ceramics. Here we demonstrate a structural transformation accompanied by shear deformation from an original -oriented body-centred cubic structure to a -oriented face-centred cubic lattice, captured at crack tips during the straining of molybdenum inside a transmission electron microscope at room temperature. The face-centred cubic domains then revert into -oriented body-centred cubic domains, equivalent to a lattice rotation of 54.7°, and ~15.4% tensile strain is reached. The face-centred cubic structure appears to be a well-defined metastable state, as evidenced by scanning transmission electron microscopy and nanodiffraction, the Nishiyama-Wassermann and Kurdjumov-Sachs relationships between the face-centred cubic and body-centred cubic structures and molecular dynamics simulations. Our findings reveal a deformation mechanism for elemental metals under high-stress deformation conditions.

  7. Application and Realization of the Computer Animation Design Based on Improved Cubic B-spline Curves

    Directory of Open Access Journals (Sweden)

    Ni Na

    2015-01-01

    Full Text Available Based on the application of the cubic B-spline curves in the computer animation design, taking into account the security and confidentiality of the information, this paper improves the animation design techniques by the use of the improved cubic B-spline curves. Finally, this paper provides the relevant C language programs of the animation design.

  8. The Normals to a Parabola and the Real Roots of a Cubic

    Science.gov (United States)

    Bains, Majinder S.; Thoo, J. B.

    2007-01-01

    The geometric problem of finding the number of normals to the parabola y = x[squared] through a given point is equivalent to the algebraic problem of finding the number of distinct real roots of a cubic equation. Apollonius solved the former problem, and Cardano gave a solution to the latter. The two problems are bridged by Neil's (semi-cubical)…

  9. Cubic Invariant Spherical Surface Harmonics in Conjunction With Diffraction Strain Pole-Figures

    NARCIS (Netherlands)

    Brakman, C.M.

    1986-01-01

    Four kinds of cubic invariant spherical surface harmonics are introduced. It has been shown previously that these harmonics occur in the equations relating measured diffraction (line-shift) elastic strain and macro-stresses generating these strains for the case of textured cubic materials. As a cons

  10. Stability of the high-pressure body-centered-cubic phase of helium

    NARCIS (Netherlands)

    Frenkel, D.

    1986-01-01

    This paper report absolute free-energy calculations of the fluid, body-centered-cubic, and face-centered-cubic phases of helium at T=327.04 K. We find that at and around this temperature the model potential proposed by Aziz et al. doe not yield a stable bcc phase. Quantum corrections do not alter th

  11. Stability of the high-pressure body-centered-cubic phase of helium

    OpenAIRE

    Frenkel, D.

    1987-01-01

    This paper report absolute free-energy calculations of the fluid, body-centered-cubic, and face-centered-cubic phases of helium at T=327.04 K. We find that at and around this temperature the model potential proposed by Aziz et al. doe not yield a stable bcc phase. Quantum corrections do not alter this conclusion

  12. Comparison of Dust Lattice Waves in Three-Dimensional Cubic Configurations

    Institute of Scientific and Technical Information of China (English)

    B. Farokhi; A. Hameditabar

    2012-01-01

    A three-dimensional (3D) dusty plasma crystalline with cubic configurations is considered. We calculate the interaction between particles up to distance √2a, implying the second-neighbor interactions for the simple cubic structure, the third-neighbor interactions for the body-centered cubic structure, and the forth-neighbor interactions the for face-centered cubic structure. Longitudinal and transverse dispersion relations are derived in arbitrary directions. The dispersion relations are studied in special directions, I.e. (1,0,0), (l,l,0)/√2, and (1,1, l)/√3- Study of dispersion relations with more neighbor interactions show that in some cases the results change physically.%A three-dimensional (3D) dusty plasma crystalline with cubic configurations is considered.We calculate the interaction between particles up to distance (√2)a,implying the second-neighbor interactions for the simple cubic structure,the third-neighbor interactions for the body-centered cubic structure,and the forth-neighbor interactions the for face-centered cubic structure.Longitudinal and transverse dispersion relations are derived in arbitrary directions.The dispersion relations are studied in special directions,i.e.(1,0,0),(1,1,0)/(√2),and (1,1,1)/(√3).Study of dispersion relations with more neighbor interactions show that in some cases the results change physically.

  13. Extending a Property of Cubic Polynomials to Higher-Degree Polynomials

    Science.gov (United States)

    Miller, David A.; Moseley, James

    2012-01-01

    In this paper, the authors examine a property that holds for all cubic polynomials given two zeros. This property is discovered after reviewing a variety of ways to determine the equation of a cubic polynomial given specific conditions through algebra and calculus. At the end of the article, they will connect the property to a very famous method…

  14. Thermodynamic properties of the cubic plutonium hydride solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Haschke, J M

    1981-12-01

    Pressure, temperature, and composition data for the cubic solid solution plutonium hydride phase, PuH/sub x/, have been measured by microbalance methods. Integral enthalpies and entropies of formation have been evaluated for the composition range 1.90 less than or equal to X less than or equal to 3.00. At 550/sup 0/K, ..delta..H/sup 0/ /sub f/(PuH/sub x/(s)) varies linearly from approximately (-38 +- 1) kcal mol/sup -1/ at PuH/sub 190/ to (-50 +- 1 kcal mol/sup -1/) at PuH/sub 3/ /sub 00/. Thermochemical values obtained by reevaluating tensimetric data from the literature are in excellent agreement with these results. Isotopic effects have been quantified by comparing the results for hydride and deuteride, and equations are presented for predicting ..delta..H/sup 0/ /sub f/ and ..delta..S/sup 0/ /sub f/ values for PuH/sub x/(s) and PuD/sub x/(s).

  15. Twinning of cubic diamond explains reported nanodiamond polymorphs

    Science.gov (United States)

    Németh, Péter; Garvie, Laurence A. J.; Buseck, Peter R.

    2015-12-01

    The unusual physical properties and formation conditions attributed to h-, i-, m-, and n-nanodiamond polymorphs has resulted in their receiving much attention in the materials and planetary science literature. Their identification is based on diffraction features that are absent in ordinary cubic (c-) diamond (space group: Fd-3m). We show, using ultra-high-resolution transmission electron microscope (HRTEM) images of natural and synthetic nanodiamonds, that the diffraction features attributed to the reported polymorphs are consistent with c-diamond containing abundant defects. Combinations of {113} reflection and rotation twins produce HRTEM images and d-spacings that match those attributed to h-, i-, and m-diamond. The diagnostic features of n-diamond in TEM images can arise from thickness effects of c-diamonds. Our data and interpretations strongly suggest that the reported nanodiamond polymorphs are in fact twinned c-diamond. We also report a new type of twin ( rotational), which can give rise to grains with dodecagonal symmetry. Our results show that twins are widespread in diamond nanocrystals. A high density of twins could strongly influence their applications.

  16. Diamine Functionalized Cubic Mesoporous Silica for Ibuprofen Controlled Delivery.

    Science.gov (United States)

    Sivaguru, J; Selvaraj, M; Ravi, S; Park, H; Song, C W; Chun, H H; Ha, C-S

    2015-07-01

    A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.

  17. Oriented-cycle partitions of cubic distance-transitive graphs

    CERN Document Server

    Dejter, Italo J

    2011-01-01

    The notion of a $\\mathcal C$-ultrahomogeneous (or $\\mathcal C$-UH) graph, due to D. Isaksen et al., is adapted to digraphs and applied to the cubic distance-transitive (or CDT) graphs $G$, considered as digraphs by replacing each edge with a pair of oppositely oriented arcs, where $\\mathcal C$ is formed by oriented cycles $\\vec{C_g}$ and $(k-1)$-arcs $\\vec{P_k}$, with $g=$ girth and $k=$ largest $s$ such that $G$ is $s$-arc transitive. All CDT graphs are shown to be strongly fastened $\\{C_g\\}_{P_k}$-UH graphs, ($g=$ girth). However, only seven of them behave as $\\{\\vec{C_g}\\}_{\\vec{P}_k}$-UH digraphs. Each of these seven graphs $G$ gives place to a digraph ${\\mathcal D}(G)$ whose vertices are the $(k-1)$-arcs of $G$; an arc in ${\\mathcal D}(G)$ is traced between each two $(k-1)$-arcs in a common $g$-cycle of $G$ sharing exactly one arc, while each remaining edge of ${\\mathcal D}(G)$ is associated with a reversal of $(k-1)$-arcs in $G$. It is shown that ${\\mathcal D}(G)$ has regular indegree $=$ outdegree $=2$...

  18. The Structure of the Cubic Coincident Site Lattice Rotation Group

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B W; Minich, R W; Rudd, R E; Kumar, M

    2004-01-13

    This work is intended to be a mathematical underpinning for the field of grain boundary engineering and its relatives. The interrelationships within the set of rotations producing coincident site lattices in cubic crystals are examined in detail. Besides combining previously established but widely scattered results into a unified context, the present work details newly developed representations of the group structure in terms of strings of generators (based on quaternionic number theory, and including uniqueness proofs and rules for algebraic manipulation) as well as an easily visualized topological network model. Important results that were previously obscure or not universally understood (e.g. the {Sigma} combination rule governing triple junctions) are clarified in these frameworks. The methods also facilitate several general observations, including the very different natures of twin-limited structures in two and three dimensions, the inadequacy of the {Sigma} combination rule to determine valid quadruple nodes, and a curious link between allowable grain boundary assignments and the four-color map theorem. This kind of understanding is essential to the generation of realistic statistical models of grain boundary networks (particularly in twin-dominated systems) and is especially applicable to the field of grain boundary engineering.

  19. Hardness analysis of cubic metal mononitrides from first principles

    Science.gov (United States)

    Fulcher, B. D.; Cui, X. Y.; Delley, B.; Stampfl, C.

    2012-05-01

    Density functional theory calculations are performed to evaluate the hardness of various cubic metal nitrides: rocksalt TiN, VN, ZrN, NbN, AlN, and SiN; zincblende AlN and BN; and diamond C for comparison. The isotropic elastic stiffness constants cij, bulk modulus K, shear modulus G, Young's modulus E, and isotropic Poisson's ratio ν¯ are calculated. From simulated uniaxial stress-strain curves, ideal strength values σmax in the [100], [110], and [111] directions are also evaluated for all systems. In particular, rocksalt AlN is found to possess both high elastic moduli and ideal strength. These quantities are then compared for correlations with existing experimental Vicker's hardness data. The bulk modulus is found to be a poor indicator of hardness, while E, G, 1/ν¯, and σmax all exhibit stronger correlations. With a view to circumvent the need to run computationally expensive relaxation steps, different methodologies for approximating uniaxial stress-strain curves are introduced. Utilizing the anisotropic Poisson's ratio to approximate the relaxed transverse lattice parameters at a given axial strain is a good approximation to stress-strain curves, and the ideal strengths obtained in this way exhibit strong correlations to experimental Vicker's hardness values.

  20. Assembly of body-centered cubic crystals in hard spheres.

    Science.gov (United States)

    Xu, W-S; Sun, Z-Y; An, L-J

    2011-05-01

    We investigate the crystallization of monodisperse hard spheres confined by two square patterned substrates (possessing the basic character of the body-centered cubic (bcc) crystal structure) at varying substrate separations via molecular dynamics simulation. Through slowly increasing the density of the system, we find that crystallization under the influence of square patterned substrates can set in at lower densities compared with the homogeneous crystallization. As the substrate separation decreases, the density, where crystallization occurs (i.e., pressure drops), becomes small. Moreover, two distinct regimes are identified in the plane of bcc particle fraction and density for the separation range investigated. For large substrate separations, the bcc particle fraction displays a local maximum as the density is increased, and the resulting formed crystals have a polycrystalline structure. However, and more importantly, another situation emerges for small substrate separations: the capillary effects (stemming from the presence of two substrates) overwhelm the bulk driving forces (stemming from the spontaneous thermal fluctuations in the bulk) during the densification, eventually resulting in the formation of a defect-free bcc crystal (unstable with respect to the bulk hard-sphere crystals) by using two square patterned substrates.

  1. Serial femtosecond crystallography of soluble proteins in lipidic cubic phase

    Directory of Open Access Journals (Sweden)

    Raimund Fromme

    2015-09-01

    Full Text Available Serial femtosecond crystallography (SFX at X-ray free-electron lasers (XFELs enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP, using a special LCP microextrusion injector. Here, it is demonstrated that LCP can also be used as a suitable carrier medium for microcrystals of soluble proteins, enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.

  2. Mechanical properties for irradiated face-centred cubic nanocrystalline metals

    Science.gov (United States)

    Xiao, X. Z.; Song, D. K.; Chu, H. J.; Xue, J. M.; Duan, H. L.

    2015-01-01

    In this paper, a self-consistent plasticity theory is proposed to model the mechanical behaviours of irradiated face-centred cubic nanocrystalline metals. At the grain level, a tensorial crystal model with both irradiation and grain size effects is applied for the grain interior (GI), whereas both grain boundary (GB) sliding with irradiation effect and GB diffusion are considered in modelling the behaviours of GBs. The elastic-viscoplastic self-consistent method with considering grain size distribution is developed to transit the microscopic behaviour of individual grains to the macroscopic properties of nanocrystals (NCs). The proposed theory is applied to model the mechanical properties of irradiated NC copper, and the feasibility and efficiency have been validated by comparing with experimental data. Numerical results show that: (i) irradiation-induced defects can lead to irradiation hardening in the GIs, but the hardening effect decreases with the grain size due to the increasing absorption of defects by GBs. Meanwhile, the absorbed defects would make the GBs softer than the unirradiated case. (ii) There exists a critical grain size for irradiated NC metals, which separates the grain size into the irradiation hardening dominant region (above the critical size) and irradiation softening dominant region (below the critical size). (iii) The distribution of grain size has a significant influence on the mechanical behaviours of both irradiated and unirradiated NCs. The proposed model can offer a valid theoretical foundation to study the irradiation effect on NC materials. PMID:27547091

  3. Cubic-interaction-induced deformations of higher-spin symmetries

    CERN Document Server

    Joung, Euihun

    2013-01-01

    The deformations of higher-spin symmetries induced by cubic interactions of symmetric massless bosonic fields are analyzed within the metric-like formalism. Our analysis amends the existing classification according to gauge-algebra deformations taking into account also gauge-transformation deformations. In particular, we identify a class of couplings which leave the gauge algebra Abelian but deform one (out of three) gauge transformation, and another class of couplings which deform all three gauge transformations in (A)dS but only two in the flat-space limit. The former class is related to higher-spin algebra multiplets (representations of the global algebra) together with the massless-massive-massive couplings, which we also briefly discuss. The latter class is what makes (A)dS a distinguished background for higher-spin interactions and includes in particular the gravitational interactions of higher-spin fields, retrospectively accounting for the Fradkin-Vasiliev solution to the Aragon-Deser problem. We also...

  4. Can a Television Series Change Attitudes about Death? A Study of College Students and "Six Feet Under"

    Science.gov (United States)

    Schiappa, Edward; Gregg, Peter B.; Hewes, Dean E.

    2004-01-01

    This study examined the effects of viewing 10 episodes of the television series "Six Feet Under" to assess whether such programming could influence college students' attitudes about death and dying. Students were administered the Death Attitude Profile--Revised, the Multidimensional Fear of Death Scale, and the short version of the…

  5. Dynamic feet distance: A new functional assessment during treadmill locomotion in normal and thoracic spinal cord injured rats.

    Science.gov (United States)

    Diogo, Camila Cardoso; Costa, Luís Maltez da; Pereira, José Eduardo; Filipe, Vítor; Couto, Pedro Alexandre; Magalhães, Luís G; Geuna, Stefano; Armada-da-Silva, Paulo A; Maurício, Ana Colette; Varejão, Artur Severo

    2017-09-29

    Of all the detrimental effects of spinal cord injury (SCI), one of the most devastating is the disruption of the ability to perform functional movement. Very little is known on the recovery of hindlimb joint kinematics after clinically-relevant contusive thoracic lesion in experimental animal models. A new functional assessment instrument, the dynamic feet distance (DFD) was used to describe the distance between the two feet throughout the gait cycle in normal and affected rodents. The purpose of this investigation was the evaluation and characterization of the DFD during treadmill locomotion in normal and T9 contusion injured rats, using three-dimensional (3D) instrumented gait analysis. Despite that normal and injured rats showed a similar pattern in the fifth metatarsal head joints distance excursion, we found a significantly wider distance between the feet during the entire gait cycle following spinal injury. This is the first study to quantify the distance between the two feet, throughout the gait cycle, and the biomechanical adjustments made between limbs in laboratory rodents after nervous system injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study

    Science.gov (United States)

    2012-01-01

    Background An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na+]) and changes in feet volume. Methods In seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography. Results Body mass decreased by 1.8 kg (2.4%) (p 0.05). Plasma volume and urine specific gravity increased (p marathon was due to an increased fluid intake. PMID:22472466

  7. Associations between oxidized LDL to LDL ratio, HDL and vascular calcification in the feet of hemodialysis patients.

    Science.gov (United States)

    An, Won Suk; Kim, Seong-Eun; Kim, Ki-Hyun; Bae, Hae-Rahn; Rha, Seo-Hee

    2009-01-01

    Cardiovascular mortality is associated with vascular calcification (VC) in hemodialysis (HD) patients. The present study was designed to find factors related with medial artery calcification on the plain radiography of feet by comparing C-reactive protein (CRP), plasminogen activator inhibitor type 1 (PAI-1) and lipid profile including oxidized low density lipoprotein (ox-LDL) and to elucidate associations among these factors in HD patients. Forty-eight HD patients were recruited for this study. VC in the feet was detected in 18 patients (37.5%) among total patients and 12 patients (85.7%) among diabetic patients. Diabetes, cardiovascular disease (CVD), pulse pressure, ox-LDL/LDL were higher and high density lipoprotein (HDL) was lower in patients with VC than in patients without VC. Negative associations were found between HDL and CRP, PAI-1. PAI-1 had positive association with ox-LDL/LDL. History of CVD was the only determinant of vascular calcification on the plain radiography of feet. Ox-LDL/LDL, HDL, CRP, and PAI-1 were closely related with one another in HD patients. History of CVD is the most important factor associated with the presence of VC and low HDL and relatively high oxidized LDL/LDL ratio may affect VC formation on the plain radiography in the feet of HD patients.

  8. A High Percentage of Beef Bull Pictures in Semen Catalogues Have Feet and Lower Legs that Are Not Visible

    Directory of Open Access Journals (Sweden)

    Marcy K. Franks

    2015-07-01

    Full Text Available A total of 1379 beef bull pictures were surveyed to determine visibility of feet and legs from four American semen company websites. Five different breeds were represented: Angus, Red Angus, Hereford (polled and horned, Simmental, and Charolais. In addition to visibility, data on other variables were collected to establish frequencies and correlations. These included breed, color, material that obscured visibility, such as grass, picture taken at livestock show or outside, semen company, photographer, video, and age of bull. A foot and leg visibility score was given to each bull picture. Only 19.4% of the pictures had fully visible feet and legs. Both the hooves and dewclaws were hidden on 32.5% of the pictures. Correlation between bull’s birthdate and the first four visibility scores was statistically significant (P < 0.0001. As age increased the feet and legs were more likely to be visible in the bull’s picture. This may possibly be due to greater availability of both photo editing software and digital photography. One positive finding was that 6% of the bulls had a video of the bull walking which completely showed his feet and legs.

  9. Lucy's flat feet: the relationship between the ankle and rearfoot arching in early hominins.

    Directory of Open Access Journals (Sweden)

    Jeremy M DeSilva

    Full Text Available BACKGROUND: In the Plio-Pleistocene, the hominin foot evolved from a grasping appendage to a stiff, propulsive lever. Central to this transition was the development of the longitudinal arch, a structure that helps store elastic energy and stiffen the foot during bipedal locomotion. Direct evidence for arch evolution, however, has been somewhat elusive given the failure of soft-tissue to fossilize. Paleoanthropologists have relied on footprints and bony correlates of arch development, though little consensus has emerged as to when the arch evolved. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present evidence from radiographs of modern humans (n = 261 that the set of the distal tibia in the sagittal plane, henceforth referred to as the tibial arch angle, is related to rearfoot arching. Non-human primates have a posteriorly directed tibial arch angle, while most humans have an anteriorly directed tibial arch angle. Those humans with a posteriorly directed tibial arch angle (8% have significantly lower talocalcaneal and talar declination angles, both measures of an asymptomatic flatfoot. Application of these results to the hominin fossil record reveals that a well developed rearfoot arch had evolved in Australopithecus afarensis. However, as in humans today, Australopithecus populations exhibited individual variation in foot morphology and arch development, and "Lucy" (A.L. 288-1, a 3.18 Myr-old female Australopithecus, likely possessed asymptomatic flat feet. Additional distal tibiae from the Plio-Pleistocene show variation in tibial arch angles, including two early Homo tibiae that also have slightly posteriorly directed tibial arch angles. CONCLUSIONS/SIGNIFICANCE: This study finds that the rearfoot arch was present in the genus Australopithecus. However, the female Australopithecus afarensis "Lucy" has an ankle morphology consistent with non-pathological flat-footedness. This study suggests that, as in humans today, there was variation in arch

  10. Cold hands, warm feet: sleep deprivation disrupts thermoregulation and its association with vigilance.

    Science.gov (United States)

    Romeijn, Nico; Verweij, Ilse M; Koeleman, Anne; Mooij, Anne; Steimke, Rosa; Virkkala, Jussi; van der Werf, Ysbrand; Van Someren, Eus J W

    2012-12-01

    Vigilance is affected by induced and spontaneous skin temperature fluctuations. Whereas sleep deprivation strongly affects vigilance, no previous study examined in detail its effect on human skin temperature fluctuations and their association with vigilance. In a repeated-measures constant routine design, skin temperatures were assessed continuously from 14 locations while performance was assessed using a reaction time task, including eyes-open video monitoring, performed five times a day for 2 days, after a normal sleep or sleep deprivation night. Participants were seated in a dimly lit, temperature-controlled laboratory. Eight healthy young adults (five males, age 22.0 ± 1.8 yr (mean ± standard deviation)). One night of sleep deprivation. Mixed-effect regression models were used to evaluate the effect of sleep deprivation on skin temperature gradients of the upper (ear-mastoid), middle (hand-arm), and lower (foot-leg) body, and on the association between fluctuations in performance and in temperature gradients. Sleep deprivation induced a marked dissociation of thermoregulatory skin temperature gradients, indicative of attenuated heat loss from the hands co-occurring with enhanced heat loss from the feet. Sleep deprivation moreover attenuated the association between fluctuations in performance and temperature gradients; the association was best preserved for the upper body gradient. Sleep deprivation disrupts coordination of fluctuations in thermoregulatory skin temperature gradients. The dissociation of middle and lower body temperature gradients may therefore be evaluated as a marker for sleep debt, and the upper body gradient as a possible aid in vigilance assessment when sleep debt is unknown. Importantly, our findings suggest that sleep deprivation affects the coordination between skin blood flow fluctuations and the baroreceptor-mediated cardiovascular regulation that prevents venous pooling of blood in the lower limbs when there is the orthostatic

  11. Risks to feet in the top end: outcomes of diabetic foot complications.

    Science.gov (United States)

    O'Rourke, Ian; Heard, Sam; Treacy, John; Gruen, Russell; Whitbread, Cherie

    2002-04-01

    The foot complications of diabetes are severe, disabling, costly and common in the Northern Territory. An understanding of the pathogenesis, the disease spectrum and treatment efficacy, however, is poor. The patterns of disease are documented in the present study; factors associated with good and poor outcomes are identified; and improved management strategies are proposed. All patients presenting to the High Risk Foot Service at Royal Darwin Hospital between March 1997 and March 2000 were included in the present study, and details regarding the status of their feet, their demographics, their treatment and their outcomes were recorded prospectively. Logistic regression analysis was undertaken to determine associations between factors of interest and outcomes of healing and amputation. One hundred and twenty-six patients were recorded, 41% of whom had neuropathic ulcers and 63% of whom had severe disease at presentation. Two types of diabetic foot pathology were recognized that are not usually classified: acute injury without neuropathy (10%) and deep soft tissue infection alone (9%).Thirty-seven percent and 23% of patients required minor and major amputations, respectively. The total number of hospital bed-days was 5813. Total contact casting was associated with good healing rates in 16 patients. Major amputation was associated with ischaemia, severe disease at presentation and increasing age. Patterns of diabetic foot disease which are not commonly recognized are described in the present study; the severity and cost of the problem are documented; and some factors which lead to poor outcome, such as late presentation, are identified. Attention should be paid, through a multidisciplinary team, to timely referral from primary care, patient education, total contact casts and appropriate revascularization.

  12. Biomechanical characteristics, patient preference and activity level with different prosthetic feet: a randomized double blind trial with laboratory and community testing.

    Science.gov (United States)

    Raschke, Silvia U; Orendurff, Michael S; Mattie, Johanne L; Kenyon, David E A; Jones, O Yvette; Moe, David; Winder, Lorne; Wong, Angie S; Moreno-Hernández, Ana; Highsmith, M Jason; J Sanderson, David; Kobayashi, Toshiki

    2015-01-02

    Providing appropriate prosthetic feet to those with limb loss is a complex and subjective process influenced by professional judgment and payer guidelines. This study used a small load cell (Europa™) at the base of the socket to measure the sagittal moments during walking with three objective categories of prosthetic feet in eleven individuals with transtibial limb loss with MFCL K2, K3 and K4 functional levels. Forefoot stiffness and hysteresis characteristics defined the three foot categories: Stiff, Intermediate, and Compliant. Prosthetic feet were randomly assigned and blinded from participants and investigators. After laboratory testing, participants completed one week community wear tests followed by a modified prosthetics evaluation questionnaire to determine if a specific category of prosthetic feet was preferred. The Compliant category of prosthetic feet was preferred by the participants (P=0.025) over the Stiff and Intermediate prosthetic feet, and the Compliant and Intermediate feet had 15% lower maximum sagittal moments during walking in the laboratory (P=0.0011) compared to the Stiff feet. The activity level of the participants did not change significantly with any of the wear tests in the community, suggesting that each foot was evaluated over a similar number of steps, but did not inherently increase activity. This is the first randomized double blind study in which prosthetic users have expressed a preference for a specific biomechanical characteristic of prosthetic feet: those with lower peak sagittal moments were preferred, and specifically preferred on slopes, stairs, uneven terrain, and during turns and maneuvering during real world use.

  13. Stable vortex solitons in a vectorial cubic-quintic model

    Energy Technology Data Exchange (ETDEWEB)

    Mihalache, D [Department of Theoretical Physics, Institute of Atomic Physics, PO Box MG-6, Bucharest (Romania); Mazilu, D [Department of Theoretical Physics, Institute of Atomic Physics, PO Box MG-6, Bucharest (Romania); Malomed, B A [Department of Interdisciplinary Studies, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Lederer, F [Institute of Solid State Theory and Theoretical Optics, Friedrich-Schiller Universitaet Jena, Max-Wien-Platz 1, D-07743, Jena (Germany)

    2004-05-01

    We investigate the stability of vectorial (two-component) vortex solitons of two types. Their stationary shapes are identical, but their stability (which is the most important issue for spinning solitons) is drastically different. These are solitons with vorticities (S,S) and (S,-S) in the two components. The analysis is performed in a vectorial cubic-quintic model, with the two components nonlinearly coupled by the incoherent cross-phase-modulation interaction, but we expect that the results are quite generic. The stability was investigated by means of computing eigenvalues of perturbations around the stationary solitons, as well as in direct simulations. We also report new analytical results for the well-known problem of the description of the stationary form of scalar solitons in media of this type. The analytical results explain the shape of the spinning solitons, and the strong dependence of their norm (power) on the vorticity, in both the 2D and 3D cases. In this paper we also give the first estimate of the physical characteristics (power and radius) of the stable solitons with different values of S, making use of recently measured values of the necessary nonlinear parameters. All the two-component solitons of type (S,-S) are unstable. In contrast, those of type (S,S) have their stability regions, the size of which strongly depends on S. An unstable soliton always splits into a set of separating zero-spin ones, in precise compliance with the azimuthal index of the most unstable perturbation eigenmode. Direct simulations demonstrate that stable solitons readily self-trap from arbitrary initial pulses which belong to their topological class.

  14. Weekly LiDAR snow depth mapping for operational snow hydrology - the NASA JPL Airborne Snow Observatory (Invited)

    Science.gov (United States)

    Deems, J. S.; Painter, T. H.; McGurk, B. J.

    2013-12-01

    Operational hydrologic simulation and forecasting in snowmelt-dominated watersheds currently relies on indices of snow accumulation and melt from measurements at a small number of point locations or geographically-limited manual surveys. These data sources cannot adequately characterize the spatial distribution of snow depth/water equivalent, which is the primary determinant of snowpack volume and runoff rates. The NASA JPL Airborne Snow Observatory's airborne laser scanning system maps snow depth at high spatial and temporal resolutions, providing an unprecedented snowpack monitoring capability and enabling a new operational paradigm. In the Spring of 2013, the ASO mapped snow depth in the Tuolumne River Basin in California's Yosemite National Park on a nominally weekly basis, and provided fast-turnaround spatial snow depth and water equivalent maps to the operators of Hetch Hetchy Reservoir, the water supply for 2.5 million people on the San Francisco peninsula. These products enabled more accurate runoff simulation and optimal reservoir management in a year of very low snow accumulation. We present the initial results from this new application of multi-temporal LiDAR mapping in operational snow hydrology.

  15. Argus: An Io observer mission concept study from the 2014 NASA/JPL Planetary Science Summer School

    Science.gov (United States)

    Hays, L. E.; Holstein-Rathlou, C.; Becerra, P.; Basu, K.; Davis, B.; Fox, V. K.; Herman, J. F. C.; Hughes, A. C. G.; Keane, J. T.; Marcucci, E.; Mendez-Ramos, E.; Nelessen, A.; Neveu, M.; Parrish, N. L.; Scheinberg, A. L.; Wrobel, J. S.

    2014-12-01

    Jupiter's satellite Io represents the ideal target for studying extreme tidal heating and volcanism, two of the most important processes in the formation and evolution of planetary bodies. The 2011 Planetary Decadal Survey identified an Io Observer as a high-priority New Frontiers class mission to be considered for the decade 2013-2022. In response to the 2009 New Frontiers Announcement of Opportunity, we propose a mission concept for an Io Observer mission, named Argus (after the mythical watchman of Io), developed by the students of the August 2014 session of the Planetary Science Summer School hosted by NASA's Jet Propulsion Laboratory, together with JPL's Team X. The goals of our mission are: (i) Study the effects of tidal heating and its implications for habitability in the Solar System and beyond; (ii) Investigate active lava flows on Io as an analog for early Earth; (iii) Analyze the interaction of Io with the Jovian system through material exchange and magnetospheric activity; (iv) Study the internal structure of Io, as well as its chemical and tectonic history in order to gain insight into its formation and that of the other Galilean satellites.

  16. Mission to the Trojan Asteroids: lessons learned during a JPL Planetary Science Summer School mission design exercise

    CERN Document Server

    Diniega, Serina; Balcerski, Jeffrey; Carande, Bryce; Diaz-Silva, Ricardo A; Fraeman, Abigail A; Guzewich, Scott D; Hudson, Jennifer; Nahm, Amanda L; Potter-McIntyre, Sally; Route, Matthew; Urban, Kevin D; Vasisht, Soumya; Benneke, Bjoern; Gil, Stephanie; Livi, Roberto; Williams, Brian; Budney, Charles J; Lowes, Leslie L; 10.1016/j.pss.2012.11.011

    2013-01-01

    The 2013 Planetary Science Decadal Survey identified a detailed investigation of the Trojan asteroids occupying Jupiter's L4 and L5 Lagrange points as a priority for future NASA missions. Observing these asteroids and measuring their physical characteristics and composition would aid in identification of their source and provide answers about their likely impact history and evolution, thus yielding information about the makeup and dynamics of the early Solar System. We present a conceptual design for a mission to the Jovian Trojan asteroids: the Trojan ASteroid Tour, Exploration, and Rendezvous (TASTER) mission, that is consistent with the NASA New Frontiers candidate mission recommended by the Decadal Survey and the final result of the 2011 NASA-JPL Planetary Science Summer School. Our proposed mission includes visits to two Trojans in the L4 population: a 500 km altitude fly-by of 1999 XS143, followed by a rendezvous with and detailed observations of 911 Agamemnon at orbital altitudes of 1000 - 100 km over ...

  17. Polyol synthesis and characterizations of cubic ZrO{sub 2}:Eu{sup 3+} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Meetei, S. Dhiren [Department of Physics, Manipur University, Canchipur-795 003, Imphal (India); Singh, Sh. Dorendrajit, E-mail: dorendrajit@yahoo.co.in [Department of Physics, Manipur University, Canchipur-795 003, Imphal (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer By polyol route nanocrystalline cubic ZrO{sub 2}:Eu{sup 3+} can be synthesized. Black-Right-Pointing-Pointer Cubic phase is the most desirable phase of zirconia. Black-Right-Pointing-Pointer Distinguishing cubic from tetragonal phase is difficult. Black-Right-Pointing-Pointer Characterizations of the samples are done by XRD, TEM, FTIR and PL. Black-Right-Pointing-Pointer Eu{sup 3+} emission peaks vary as charge transfer state in ZrO{sub 2}:Eu{sup 3+}. - Abstract: Nanocrystalline ZrO{sub 2} and ZrO{sub 2}:Eu{sup 3+} were synthesized by polyol route. The x-ray diffraction (XRD) pattern of ZrO{sub 2} shows presence of both monoclinic and tetragonal phase of zirconia, while that of ZrO{sub 2}:Eu{sup 3+} show cubic structure. Cubic phase is the most desired phase of zirconia. However, it is difficult to distinguish between the tetragonal and cubic phases solely from XRD study. Therefore, the characterizations of cubic phase in the doped samples are substantiated by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and photoluminescence (PL) studies. Interplaner spacing, d{sub hkl} are calculated from the selected area electron diffraction (SAED) rings and they are found to be consistent with that of cubic zirconia. FT-IR spectra of doped and undoped samples are found to be different. This is attributed to the presence of both monoclinic and tetragonal phase in the undoped sample and only cubic phase in the doped samples. PL excitation and emission spectra of the samples are studied. The asymmetry ratio is found to be less than that of the reported tetragonal phase indicating that the present analyzing samples have higher symmetry than tetragonal phase. Variations of Eu{sup 3+} emission peaks are observed as that of charge transfer state (CTS).

  18. Collapse of ultrashort spatiotemporal pulses described by the cubic generalized Kadomtsev-Petviashvili equation

    CERN Document Server

    Leblond, Hervé; Mihalache, Dumitru; 10.1103/PHYSREVA.81.033824

    2011-01-01

    By using a reductive perturbation method, we derive from Maxwell-Bloch equations a cubic generalized Kadomtsev-Petviashvili equation for ultrashort spatiotemporal optical pulse propagation in cubic (Kerr-like) media without the use of the slowly varying envelope approximation. We calculate the collapse threshold for the propagation of few-cycle spatiotemporal pulses described by the generic cubic generalized Kadomtsev-Petviashvili equation by a direct numerical method and compare it to analytic results based on a rigorous virial theorem. Besides, typical evolution of the spectrum (integrated over the transverse spatial coordinate) is given and a strongly asymmetric spectral broadening of ultrashort spatiotemporal pulses during collapse is evidenced.

  19. Mechanism of the body-centered cubic--hexagonal close-packed phase transition in iron.

    Science.gov (United States)

    Bassett, W A; Huang, E

    1987-11-06

    The transition from body-centered cubic to hexagonal close-packed phase in iron has been studied in a diamond anvil cell with synchrotron radiation. The hexagonal close-packed phase, when it first appears, has a ratio of lattice parameters that is significantly larger than normal. This is attributed to a displacive mechanism that causes a distortion of the hexagonal close-packed structure in a body-centered cubic matrix. The hexagonal close-packed phase adjacent to a boundary with the body-centered cubic phase is stretched in the c direction and compressed in the a direction when it first forms.

  20. Soil iron and aluminium concentrations and feet hygiene as possible predictors of Podoconiosis occurrence in Kenya.

    Science.gov (United States)

    Muli, Jacinta; Gachohi, John; Kagai, Jim

    2017-08-01

    Podoconiosis (mossy foot) is a neglected non-filarial elephantiasis considered to be caused by predisposition to cumulative contact of uncovered feet to irritative red clay soil of volcanic origins in the tropical regions. Data from structured observational studies on occurrence of Podoconiosis and related factors are not available in Kenya. To establish the occurrence and aspects associated with Podoconiosis, a cross-sectional survey was implemented in an area located within 30 km from the foot of volcanic Mount Longonot in the Great Rift Valley in Kenya. Five villages and 385 households were selected using multistage and systematic random sampling procedures respectively during the survey. Podoconiosis was determined by triangulating (1) the clinical diagnosis, (2) molecular assaying of sputum samples to rule out Wuchereria bancrofti microfilaria and (3) determining the concentration of six elements and properties in the soil known to be associated with Podoconiosis. A structured questionnaire was used to identify possible risk factors. Univariable and multivariable Poisson regression analyses were carried out to determine factors associated with Podoconiosis. Thirteen participants were clinically positive for Podoconiosis giving an overall prevalence of 3.4%. The prevalence ranged between 0% and 18.8% across the five villages. Molecular assay for W. bancrofti test turned negative in the 13 samples. The following factors were positively associated with the Podoconiosis prevalence (Pwearing shoes, (vi) soil pH, and (vii) village. Unexpectedly, the concentration of soil minerals previously thought to be associated with Podoconiosis was found to be negatively associated with the Podoconiosis prevalence (Pwearing shoes and village turned out significant (P≤0.05). By modeling the different soil mineral concentrations and pH while adjusting for the variable frequency of wearing shoes, only iron concentration was significant and in the negative dimension (P≤0